Merge remote-tracking branch 'engelsystem/feature-igel-rewrite'

# Conflicts:
#	includes/controller/angeltypes_controller.php
#	includes/pages/admin_groups.php
#	includes/pages/user_settings.php
#	includes/sys_page.php
#	src/Exceptions/Handler.php
#	src/Http/Request.php

45 files changed, 232 insertions, 644 deletions

diff --git a/includes/controller/event_config_controller.php b/includes/controller/event_config_controller.php
index dcdcf54a..7d11ecb4 100644
--- a/includes/controller/event_config_controller.php
+++ b/includes/controller/event_config_controller.php
@@ -91,7 +91,7 @@ function event_config_edit_controller()
         }
 
         if ($valid) {
-            $result = EventConfig_update(
+            EventConfig_update(
                 $event_name,
                 $buildup_start_date,
                 $event_start_date,
@@ -100,10 +100,6 @@ function event_config_edit_controller()
                 $event_welcome_msg
             );
 
-            if ($result === false) {
-                engelsystem_error('Unable to update event config.');
-            }
-
             engelsystem_log(
                 'Changed event config: $event_name, $event_welcome_msg, '
                 . date('Y-m-d', $buildup_start_date) . ', ' . date('Y-m-d', $event_start_date) . ', '
diff --git a/includes/controller/rooms_controller.php b/includes/controller/rooms_controller.php
index 81b0113e..d6da9709 100644
--- a/includes/controller/rooms_controller.php
+++ b/includes/controller/rooms_controller.php
@@ -80,10 +80,7 @@ function rooms_controller()
         case 'list':
         default:
             redirect(page_link_to('admin_rooms'));
-            break;
     }
-
-    exit;
 }
 
 /**
diff --git a/includes/controller/shift_entries_controller.php b/includes/controller/shift_entries_controller.php
index 3890241d..148b19fb 100644
--- a/includes/controller/shift_entries_controller.php
+++ b/includes/controller/shift_entries_controller.php
@@ -43,7 +43,7 @@ function shift_entry_add_controller()
         $type = AngelType($type_id);
     } else {
         // TODO: Move queries to model
-        $type = DB::select('
+        $type = DB::selectOne('
             SELECT *
             FROM `UserAngelTypes`
             JOIN `AngelTypes` ON (`UserAngelTypes`.`angeltype_id` = `AngelTypes`.`id`)
@@ -56,7 +56,6 @@ function shift_entry_add_controller()
                 )
             )
         ', [$type_id, $user['UID']]);
-        $type = array_shift($type);
     }
 
     if (empty($type)) {
@@ -130,7 +129,7 @@ function shift_entry_add_controller()
         }
 
         $comment = strip_request_item_nl('comment');
-        $result = ShiftEntry_create([
+        ShiftEntry_create([
             'SID'              => $shift_id,
             'TID'              => $selected_type_id,
             'UID'              => $user_id,
@@ -138,9 +137,6 @@ function shift_entry_add_controller()
             'freeloaded'       => $freeloaded,
             'freeload_comment' => $freeload_comment
         ]);
-        if ($result === false) {
-            engelsystem_error('Unable to create shift entry.');
-        }
 
         if (
             $type['restricted'] == 0
@@ -244,7 +240,7 @@ function shift_entry_delete_controller()
     }
     $entry_id = $request->input('entry_id');
 
-    $shift_entry_source = DB::select('
+    $shift_entry_source = DB::selectOne('
         SELECT
             `User`.`Nick`,
             `ShiftEntry`.`Comment`,
@@ -263,19 +259,14 @@ function shift_entry_delete_controller()
         WHERE `ShiftEntry`.`id`=?',
         [$entry_id]
     );
-    if (count($shift_entry_source) > 0) {
-        $shift_entry_source = array_shift($shift_entry_source);
-
+    if (!empty($shift_entry_source)) {
         if (!in_array('user_shifts_admin', $privileges) && (!in_array('shiftentry_edit_angeltype_supporter',
                     $privileges) || !User_is_AngelType_supporter($user, AngelType($shift_entry_source['angeltype_id'])))
         ) {
             redirect(page_link_to('user_shifts'));
         }
 
-        $result = ShiftEntry_delete($entry_id);
-        if ($result === false) {
-            engelsystem_error('Unable to delete shift entry.');
-        }
+        ShiftEntry_delete($entry_id);
 
         engelsystem_log(
             'Deleted ' . User_Nick_render($shift_entry_source) . '\'s shift: ' . $shift_entry_source['name']
diff --git a/includes/controller/shifts_controller.php b/includes/controller/shifts_controller.php
index f68f64fe..c359850f 100644
--- a/includes/controller/shifts_controller.php
+++ b/includes/controller/shifts_controller.php
@@ -141,10 +141,7 @@ function shift_edit_controller()
             $shift['start'] = $start;
             $shift['end'] = $end;
 
-            $result = Shift_update($shift);
-            if ($result === false) {
-                engelsystem_error('Unable to update shift.');
-            }
+            Shift_update($shift);
             NeededAngelTypes_delete_by_shift($shift_id);
             $needed_angel_types_info = [];
             foreach ($needed_angel_types as $type_id => $count) {
@@ -337,7 +334,6 @@ function shift_next_controller()
     }
 
     redirect(page_link_to('user_shifts'));
-    exit;
 }
 
 /**
@@ -361,9 +357,6 @@ function shifts_json_export_all_controller()
     }
 
     $shifts_source = Shifts();
-    if ($shifts_source === false) {
-        engelsystem_error('Unable to load shifts.');
-    }
 
     header('Content-Type: application/json; charset=utf-8');
     raw_output(json_encode($shifts_source));
diff --git a/includes/controller/shifttypes_controller.php b/includes/controller/shifttypes_controller.php
index 3ef2675f..4e7cd92c 100644
--- a/includes/controller/shifttypes_controller.php
+++ b/includes/controller/shifttypes_controller.php
@@ -28,10 +28,7 @@ function shifttype_delete_controller()
     }
 
     if ($request->has('confirmed')) {
-        $result = ShiftType_delete($shifttype['id']);
-        if (empty($result)) {
-            engelsystem_error('Unable to delete shifttype.');
-        }
+        ShiftType_delete($shifttype['id']);
 
         engelsystem_log('Deleted shifttype ' . $shifttype['name']);
         success(sprintf(_('Shifttype %s deleted.'), $shifttype['name']));
@@ -93,17 +90,13 @@ function shifttype_edit_controller()
 
         if ($valid) {
             if ($shifttype_id) {
-                $result = ShiftType_update($shifttype_id, $name, $angeltype_id, $description);
-                if ($result === false) {
-                    engelsystem_error('Unable to update shifttype.');
-                }
+                ShiftType_update($shifttype_id, $name, $angeltype_id, $description);
+
                 engelsystem_log('Updated shifttype ' . $name);
                 success(_('Updated shifttype.'));
             } else {
                 $shifttype_id = ShiftType_create($name, $angeltype_id, $description);
-                if ($shifttype_id === false) {
-                    engelsystem_error('Unable to create shifttype.');
-                }
+
                 engelsystem_log('Created shifttype ' . $name);
                 success(_('Created shifttype.'));
             }
@@ -150,9 +143,6 @@ function shifttype_controller()
 function shifttypes_list_controller()
 {
     $shifttypes = ShiftTypes();
-    if ($shifttypes === false) {
-        engelsystem_error('Unable to load shifttypes.');
-    }
 
     return [
         shifttypes_title(),
diff --git a/includes/controller/user_angeltypes_controller.php b/includes/controller/user_angeltypes_controller.php
index b427e868..fa4f5777 100644
--- a/includes/controller/user_angeltypes_controller.php
+++ b/includes/controller/user_angeltypes_controller.php
@@ -214,10 +214,7 @@ function user_angeltype_delete_controller()
     }
 
     if ($request->has('confirmed')) {
-        $result = UserAngelType_delete($user_angeltype);
-        if ($result === false) {
-            engelsystem_error('Unable to delete user angeltype.');
-        }
+        UserAngelType_delete($user_angeltype);
 
         $success_message = sprintf(_('User %s removed from %s.'), User_Nick_render($user_source), $angeltype['name']);
         engelsystem_log($success_message);
@@ -421,6 +418,5 @@ function user_angeltypes_controller()
             return user_angeltype_add_controller();
         default:
             redirect(page_link_to('angeltypes'));
-            exit;
     }
 }
diff --git a/includes/controller/users_controller.php b/includes/controller/users_controller.php
index b8a1fdbd..e8cb1b27 100644
--- a/includes/controller/users_controller.php
+++ b/includes/controller/users_controller.php
@@ -76,10 +76,7 @@ function user_delete_controller()
         }
 
         if ($valid) {
-            $result = User_delete($user_source['UID']);
-            if ($result === false) {
-                engelsystem_error('Unable to delete user.');
-            }
+            User_delete($user_source['UID']);
 
             mail_user_delete($user_source);
             success(_('User deleted.'));
@@ -166,10 +163,7 @@ function user_edit_vouchers_controller()
         if ($valid) {
             $user_source['got_voucher'] = $vouchers;
 
-            $result = User_update($user_source);
-            if ($result === false) {
-                engelsystem_error('Unable to update user.');
-            }
+            User_update($user_source);
 
             success(_('Saved the number of vouchers.'));
             engelsystem_log(User_Nick_render($user_source) . ': ' . sprintf('Got %s vouchers',
@@ -265,10 +259,6 @@ function users_list_controller()
     }
 
     $users = Users($order_by);
-    if ($users === false) {
-        engelsystem_error('Unable to load users.');
-    }
-
     foreach ($users as &$user) {
         $user['freeloads'] = count(ShiftEntries_freeloaded_by_user($user));
     }
diff --git a/includes/model/AngelType_model.php b/includes/model/AngelType_model.php
index d437f526..bc535667 100644
--- a/includes/model/AngelType_model.php
+++ b/includes/model/AngelType_model.php
@@ -77,31 +77,25 @@ function AngelType_contact_info($angeltype)
  * Delete an Angeltype.
  *
  * @param array $angeltype
- * @return bool
  */
 function AngelType_delete($angeltype)
 {
-    $result = DB::delete('
+    DB::delete('
       DELETE FROM `AngelTypes`
       WHERE `id`=?
       LIMIT 1
     ', [$angeltype['id']]);
-    if (is_null($result)) {
-        engelsystem_error('Unable to delete angeltype.');
-    }
     engelsystem_log('Deleted angeltype: ' . AngelType_name_render($angeltype));
-    return true;
 }
 
 /**
  * Update Angeltype.
  *
  * @param array $angeltype The angeltype
- * @return bool
  */
 function AngelType_update($angeltype)
 {
-    $result = DB::update('
+    DB::update('
           UPDATE `AngelTypes` SET
           `name` = ?,
           `restricted` = ?,
@@ -126,15 +120,12 @@ function AngelType_update($angeltype)
             $angeltype['id'],
         ]
     );
-    if (is_null($result)) {
-        engelsystem_error('Unable to update angeltype.');
-    }
+
     engelsystem_log(
         'Updated angeltype: ' . $angeltype['name'] . ($angeltype['restricted'] ? ', restricted' : '')
         . ($angeltype['no_self_signup'] ? ', no_self_signup' : '')
         . ($angeltype['requires_driver_license'] ? ', requires driver license' : '')
     );
-    return true;
 }
 
 /**
@@ -145,7 +136,7 @@ function AngelType_update($angeltype)
  */
 function AngelType_create($angeltype)
 {
-    $result = DB::insert('
+    DB::insert('
           INSERT INTO `AngelTypes` (
               `name`,
               `restricted`,
@@ -171,9 +162,7 @@ function AngelType_create($angeltype)
             $angeltype['contact_email'],
         ]
     );
-    if (is_null($result)) {
-        engelsystem_error('Unable to create angeltype.');
-    }
+
     $angeltype['id'] = DB::getPdo()->lastInsertId();
     engelsystem_log(
         'Created angeltype: ' . $angeltype['name']
@@ -224,7 +213,7 @@ function AngelType_validate_name($name, $angeltype)
  */
 function AngelTypes_with_user($user)
 {
-    $result = DB::select('
+    return DB::select('
       SELECT `AngelTypes`.*,
       `UserAngelTypes`.`id` AS `user_angeltype_id`,
       `UserAngelTypes`.`confirm_user_id`,
@@ -233,11 +222,6 @@ function AngelTypes_with_user($user)
       LEFT JOIN `UserAngelTypes` ON `AngelTypes`.`id`=`UserAngelTypes`.`angeltype_id`
       AND `UserAngelTypes`.`user_id` = ?
       ORDER BY `name`', [$user['UID']]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load angeltypes.');
-    }
-    return $result;
 }
 
 /**
@@ -247,15 +231,10 @@ function AngelTypes_with_user($user)
  */
 function AngelTypes()
 {
-    $result = DB::select('
+    return DB::select('
       SELECT *
       FROM `AngelTypes`
       ORDER BY `name`');
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load angeltypes.');
-    }
-    return $result;
 }
 
 /**
@@ -266,10 +245,6 @@ function AngelTypes()
 function AngelType_ids()
 {
     $result = DB::select('SELECT `id` FROM `AngelTypes`');
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load angeltypes.');
-    }
     return select_array($result, 'id', 'id');
 }
 
@@ -281,18 +256,8 @@ function AngelType_ids()
  */
 function AngelType($angeltype_id)
 {
-    $angelType_source = DB::select(
+    return DB::selectOne(
         'SELECT * FROM `AngelTypes` WHERE `id`=?',
         [$angeltype_id]
     );
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load angeltype.');
-    }
-
-    if (empty($angelType_source)) {
-        return null;
-    }
-
-    return array_shift($angelType_source);
 }
diff --git a/includes/model/EventConfig_model.php b/includes/model/EventConfig_model.php
index 112ad457..646d19c5 100644
--- a/includes/model/EventConfig_model.php
+++ b/includes/model/EventConfig_model.php
@@ -9,17 +9,7 @@ use Engelsystem\Database\DB;
  */
 function EventConfig()
 {
-    $event_config = DB::select('SELECT * FROM `EventConfig` LIMIT 1');
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load event config.');
-        return null;
-    }
-
-    if (empty($event_config)) {
-        return null;
-    }
-
-    return array_shift($event_config);
+    return DB::selectOne('SELECT * FROM `EventConfig` LIMIT 1');
 }
 
 /**
@@ -31,7 +21,7 @@ function EventConfig()
  * @param int    $event_end_date
  * @param int    $teardown_end_date
  * @param string $event_welcome_msg
- * @return bool
+ * @return int Rows updated
  */
 function EventConfig_update(
     $event_name,
diff --git a/includes/model/Message_model.php b/includes/model/Message_model.php
index ebd4b37e..9bb037af 100644
--- a/includes/model/Message_model.php
+++ b/includes/model/Message_model.php
@@ -20,11 +20,7 @@ function Message_ids()
  */
 function Message($message_id)
 {
-    $message_source = DB::select('SELECT * FROM `Messages` WHERE `id`=? LIMIT 1', [$message_id]);
-    if (empty($message_source)) {
-        return null;
-    }
-    return array_shift($message_source);
+    return DB::selectOne('SELECT * FROM `Messages` WHERE `id`=? LIMIT 1', [$message_id]);
 }
 
 /**
diff --git a/includes/model/NeededAngelTypes_model.php b/includes/model/NeededAngelTypes_model.php
index 97b085f0..d8de5e69 100644
--- a/includes/model/NeededAngelTypes_model.php
+++ b/includes/model/NeededAngelTypes_model.php
@@ -17,7 +17,7 @@ use Engelsystem\Database\DB;
  */
 function NeededAngelType_add($shift_id, $angeltype_id, $room_id, $count)
 {
-    $result = DB::insert('
+    DB::insert('
           INSERT INTO `NeededAngelTypes` ( `shift_id`, `angel_type_id`, `room_id`, `count`)
            VALUES (?, ?, ?, ?)
         ',
@@ -27,9 +27,6 @@ function NeededAngelType_add($shift_id, $angeltype_id, $room_id, $count)
             $room_id,
             $count,
         ]);
-    if ($result === false) {
-        return false;
-    }
 
     return DB::getPdo()->lastInsertId();
 }
@@ -38,22 +35,20 @@ function NeededAngelType_add($shift_id, $angeltype_id, $room_id, $count)
  * Deletes all needed angel types from given shift.
  *
  * @param int $shift_id id of the shift
- * @return int count of affected rows
  */
 function NeededAngelTypes_delete_by_shift($shift_id)
 {
-    return (int)DB::delete('DELETE FROM `NeededAngelTypes` WHERE `shift_id` = ?', [$shift_id]);
+    DB::delete('DELETE FROM `NeededAngelTypes` WHERE `shift_id` = ?', [$shift_id]);
 }
 
 /**
  * Deletes all needed angel types from given room.
  *
  * @param int $room_id id of the room
- * @return int count of affected rows
  */
 function NeededAngelTypes_delete_by_room($room_id)
 {
-    return (int)DB::delete(
+    DB::delete(
         'DELETE FROM `NeededAngelTypes` WHERE `room_id` = ?',
         [$room_id]
     );
@@ -76,9 +71,6 @@ function NeededAngelTypes_by_shift($shiftId)
         ORDER BY `room_id` DESC',
         [$shiftId]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load needed angeltypes.');
-    }
 
     // Use settings from room
     if (count($needed_angeltypes_source) == 0) {
@@ -91,9 +83,6 @@ function NeededAngelTypes_by_shift($shiftId)
         AND `count` > 0
         ORDER BY `room_id` DESC
         ', [$shiftId]);
-        if (DB::getStm()->errorCode() != '00000') {
-            engelsystem_error('Unable to load needed angeltypes.');
-        }
     }
 
     $shift_entries = ShiftEntries_by_shift($shiftId);
diff --git a/includes/model/Room_model.php b/includes/model/Room_model.php
index 17617b39..8425e5ad 100644
--- a/includes/model/Room_model.php
+++ b/includes/model/Room_model.php
@@ -17,11 +17,10 @@ function Rooms($show_all = false)
  * Delete a room
  *
  * @param int $room_id
- * @return bool
  */
 function Room_delete($room_id)
 {
-    return DB::delete('DELETE FROM `Room` WHERE `RID` = ?', [$room_id]);
+    DB::delete('DELETE FROM `Room` WHERE `RID` = ?', [$room_id]);
 }
 
 /**
@@ -35,7 +34,7 @@ function Room_delete($room_id)
  */
 function Room_create($name, $from_frab, $public, $number = null)
 {
-    $result = DB::insert('
+    DB::insert('
           INSERT INTO `Room` (`Name`, `FromPentabarf`, `show`, `Number`)
            VALUES (?, ?, ?, ?)
         ',
@@ -46,9 +45,6 @@ function Room_create($name, $from_frab, $public, $number = null)
             (int)$number,
         ]
     );
-    if (!$result) {
-        return false;
-    }
 
     return DB::getPdo()->lastInsertId();
 }
@@ -62,21 +58,11 @@ function Room_create($name, $from_frab, $public, $number = null)
  */
 function Room($room_id, $onlyVisible = true)
 {
-    $room_source = DB::select('
+    return DB::selectOne('
         SELECT *
         FROM `Room`
         WHERE `RID` = ?
         ' . ($onlyVisible ? 'AND `show` = \'Y\'' : ''),
         [$room_id]
     );
-
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
-
-    if (empty($room_source)) {
-        return null;
-    }
-
-    return array_shift($room_source);
 }
diff --git a/includes/model/ShiftEntry_model.php b/includes/model/ShiftEntry_model.php
index d7810feb..3a7254ad 100644
--- a/includes/model/ShiftEntry_model.php
+++ b/includes/model/ShiftEntry_model.php
@@ -28,10 +28,9 @@ function ShiftEntry_new()
  */
 function ShiftEntries_freeleaded_count()
 {
-    $result = DB::select('SELECT COUNT(*) FROM `ShiftEntry` WHERE `freeloaded` = 1');
-    $result = array_shift($result);
+    $result = DB::selectOne('SELECT COUNT(*) FROM `ShiftEntry` WHERE `freeloaded` = 1');
 
-    if (!is_array($result)) {
+    if (empty($result)) {
         return 0;
     }
 
@@ -102,7 +101,6 @@ function ShiftEntry_create($shift_entry)
  * Update a shift entry.
  *
  * @param array $shift_entry
- * @return bool
  */
 function ShiftEntry_update($shift_entry)
 {
@@ -120,39 +118,29 @@ function ShiftEntry_update($shift_entry)
             $shift_entry['id']
         ]
     );
-
-    return (DB::getStm()->errorCode() == '00000');
 }
 
 /**
  * Get a shift entry.
  *
  * @param int $shift_entry_id
- * @return array|false|null
+ * @return array|null
  */
 function ShiftEntry($shift_entry_id)
 {
-    $shift_entry = DB::select('SELECT * FROM `ShiftEntry` WHERE `id` = ?', [$shift_entry_id]);
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
-    if (empty($shift_entry)) {
-        return null;
-    }
-    return $shift_entry[0];
+    return DB::selectOne('SELECT * FROM `ShiftEntry` WHERE `id` = ?', [$shift_entry_id]);
 }
 
 /**
  * Delete a shift entry.
  *
  * @param int $shift_entry_id
- * @return bool
  */
 function ShiftEntry_delete($shift_entry_id)
 {
     $shift_entry = ShiftEntry($shift_entry_id);
     mail_shift_removed(User($shift_entry['UID']), Shift($shift_entry['SID']));
-    return DB::delete('DELETE FROM `ShiftEntry` WHERE `id` = ?', [$shift_entry_id]);
+    DB::delete('DELETE FROM `ShiftEntry` WHERE `id` = ?', [$shift_entry_id]);
 }
 
 /**
@@ -213,7 +201,7 @@ function ShiftEntries_finished_by_user($user)
  */
 function ShiftEntries_by_shift_and_angeltype($shift_id, $angeltype_id)
 {
-    $result = DB::select('
+    return DB::select('
             SELECT *
             FROM `ShiftEntry`
             WHERE `SID` = ?
@@ -224,10 +212,6 @@ function ShiftEntries_by_shift_and_angeltype($shift_id, $angeltype_id)
             $angeltype_id,
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load shift entries.');
-    }
-    return $result;
 }
 
 /**
diff --git a/includes/model/ShiftTypes_model.php b/includes/model/ShiftTypes_model.php
index 96a823d4..227df367 100644
--- a/includes/model/ShiftTypes_model.php
+++ b/includes/model/ShiftTypes_model.php
@@ -6,11 +6,10 @@ use Engelsystem\Database\DB;
  * Delete a shift type.
  *
  * @param int $shifttype_id
- * @return bool
  */
 function ShiftType_delete($shifttype_id)
 {
-    return DB::delete('DELETE FROM `ShiftTypes` WHERE `id`=?', [$shifttype_id]);
+    DB::delete('DELETE FROM `ShiftTypes` WHERE `id`=?', [$shifttype_id]);
 }
 
 /**
@@ -20,7 +19,6 @@ function ShiftType_delete($shifttype_id)
  * @param string $name
  * @param int    $angeltype_id
  * @param string $description
- * @return bool
  */
 function ShiftType_update($shifttype_id, $name, $angeltype_id, $description)
 {
@@ -38,8 +36,6 @@ function ShiftType_update($shifttype_id, $name, $angeltype_id, $description)
             $shifttype_id,
         ]
     );
-
-    return DB::getStm()->errorCode() == '00000';
 }
 
 /**
@@ -52,7 +48,7 @@ function ShiftType_update($shifttype_id, $name, $angeltype_id, $description)
  */
 function ShiftType_create($name, $angeltype_id, $description)
 {
-    $result = DB::insert('
+    DB::insert('
         INSERT INTO `ShiftTypes` (`name`, `angeltype_id`, `description`)
         VALUES(?, ?, ?)
         ',
@@ -63,10 +59,6 @@ function ShiftType_create($name, $angeltype_id, $description)
         ]
     );
 
-    if ($result === false) {
-        return false;
-    }
-
     return DB::getPdo()->lastInsertId();
 }
 
@@ -78,28 +70,15 @@ function ShiftType_create($name, $angeltype_id, $description)
  */
 function ShiftType($shifttype_id)
 {
-    $shifttype = DB::select('SELECT * FROM `ShiftTypes` WHERE `id`=?', [$shifttype_id]);
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load shift type.');
-    }
-    if (empty($shifttype)) {
-        return null;
-    }
-    return array_shift($shifttype);
+    return DB::selectOne('SELECT * FROM `ShiftTypes` WHERE `id`=?', [$shifttype_id]);
 }
 
 /**
  * Get all shift types.
  *
- * @return array|false
+ * @return array
  */
 function ShiftTypes()
 {
-    $result = DB::select('SELECT * FROM `ShiftTypes` ORDER BY `name`');
-
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
-
-    return $result;
+    return DB::select('SELECT * FROM `ShiftTypes` ORDER BY `name`');
 }
diff --git a/includes/model/Shifts_model.php b/includes/model/Shifts_model.php
index 21abc888..88b28998 100644
--- a/includes/model/Shifts_model.php
+++ b/includes/model/Shifts_model.php
@@ -10,11 +10,7 @@ use Engelsystem\ShiftSignupState;
  */
 function Shifts_by_room($room)
 {
-    $result = DB::select('SELECT * FROM `Shifts` WHERE `RID`=? ORDER BY `start`', [$room['RID']]);
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load shifts.');
-    }
-    return $result;
+    return DB::select('SELECT * FROM `Shifts` WHERE `RID`=? ORDER BY `start`', [$room['RID']]);
 }
 
 /**
@@ -49,7 +45,8 @@ function Shifts_by_ShiftsFilter(ShiftsFilter $shiftsFilter)
       AND NOT `Shifts`.`PSID` IS NULL) AS tmp_shifts
 
       ORDER BY `start`';
-    $result = DB::select(
+    
+    return DB::select(
         $sql,
         [
             $shiftsFilter->getStartTime(),
@@ -58,10 +55,6 @@ function Shifts_by_ShiftsFilter(ShiftsFilter $shiftsFilter)
             $shiftsFilter->getEndTime(),
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load shifts by filter.');
-    }
-    return $result;
 }
 
 /**
@@ -100,7 +93,8 @@ function NeededAngeltypes_by_ShiftsFilter(ShiftsFilter $shiftsFilter)
       WHERE `Shifts`.`RID` IN (' . implode(',', $shiftsFilter->getRooms()) . ')
       AND `start` BETWEEN ? AND ?
       AND NOT `Shifts`.`PSID` IS NULL';
-    $result = DB::select(
+
+    return DB::select(
         $sql,
         [
             $shiftsFilter->getStartTime(),
@@ -109,10 +103,6 @@ function NeededAngeltypes_by_ShiftsFilter(ShiftsFilter $shiftsFilter)
             $shiftsFilter->getEndTime(),
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load needed angeltypes by filter.');
-    }
-    return $result;
 }
 
 /**
@@ -122,7 +112,7 @@ function NeededAngeltypes_by_ShiftsFilter(ShiftsFilter $shiftsFilter)
  */
 function NeededAngeltype_by_Shift_and_Angeltype($shift, $angeltype)
 {
-    $result = DB::select('
+    return DB::selectOne('
           SELECT
               `NeededAngelTypes`.*,
               `Shifts`.`SID`,
@@ -160,13 +150,6 @@ function NeededAngeltype_by_Shift_and_Angeltype($shift, $angeltype)
             $angeltype['id']
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load needed angeltypes by filter.');
-    }
-    if (empty($result)) {
-        return null;
-    }
-    return $result[0];
 }
 
 /**
@@ -193,17 +176,13 @@ function ShiftEntries_by_ShiftsFilter(ShiftsFilter $shiftsFilter)
       WHERE `Shifts`.`RID` IN (' . implode(',', $shiftsFilter->getRooms()) . ')
       AND `start` BETWEEN ? AND ?
       ORDER BY `Shifts`.`start`';
-    $result = DB::select(
+    return DB::select(
         $sql,
         [
             $shiftsFilter->getStartTime(),
             $shiftsFilter->getEndTime(),
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load shift entries by filter.');
-    }
-    return $result;
 }
 
 /**
@@ -402,41 +381,29 @@ function Shift_signup_allowed(
  * Delete a shift by its external id.
  *
  * @param int $shift_psid
- * @return bool
  */
 function Shift_delete_by_psid($shift_psid)
 {
     DB::delete('DELETE FROM `Shifts` WHERE `PSID`=?', [$shift_psid]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
-
-    return true;
 }
 
 /**
  * Delete a shift.
  *
  * @param int $shift_id
- * @return bool
  */
 function Shift_delete($shift_id)
 {
     mail_shift_delete(Shift($shift_id));
 
-    $result = DB::delete('DELETE FROM `Shifts` WHERE `SID`=?', [$shift_id]);
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to delete shift.');
-    }
-    return $result;
+    DB::delete('DELETE FROM `Shifts` WHERE `SID`=?', [$shift_id]);
 }
 
 /**
  * Update a shift.
  *
  * @param array $shift
- * @return bool
+ * @return int Updated row count
  */
 function Shift_update($shift)
 {
@@ -444,7 +411,7 @@ function Shift_update($shift)
     $shift['name'] = ShiftType($shift['shifttype_id'])['name'];
     mail_shift_change(Shift($shift['SID']), $shift);
 
-    return (bool)DB::update('
+    return DB::update('
       UPDATE `Shifts` SET
       `shifttype_id` = ?,
       `start` = ?,
@@ -480,16 +447,13 @@ function Shift_update($shift)
  */
 function Shift_update_by_psid($shift)
 {
-    $shift_source = DB::select('SELECT `SID` FROM `Shifts` WHERE `PSID`=?', [$shift['PSID']]);
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
+    $shift_source = DB::selectOne('SELECT `SID` FROM `Shifts` WHERE `PSID`=?', [$shift['PSID']]);
 
     if (empty($shift_source)) {
-        return null;
+        throw new Exception('Shift not found.');
     }
 
-    $shift['SID'] = $shift_source[0]['SID'];
+    $shift['SID'] = $shift_source['SID'];
     return Shift_update($shift);
 }
 
@@ -497,7 +461,7 @@ function Shift_update_by_psid($shift)
  * Create a new shift.
  *
  * @param array $shift
- * @return int|false shift id or false
+ * @return int ID of the new created shift
  */
 function Shift_create($shift)
 {
@@ -528,9 +492,7 @@ function Shift_create($shift)
             time(),
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
+
     return DB::getPdo()->lastInsertId();
 }
 
@@ -543,7 +505,7 @@ function Shift_create($shift)
  */
 function Shifts_by_user($user, $include_freeload_comments = false)
 {
-    $result = DB::select('
+    return DB::select('
           SELECT `ShiftTypes`.`id` AS `shifttype_id`, `ShiftTypes`.`name`,
           `ShiftEntry`.`id`, `ShiftEntry`.`SID`, `ShiftEntry`.`TID`, `ShiftEntry`.`UID`, `ShiftEntry`.`freeloaded`, `ShiftEntry`.`Comment`,
           ' . ($include_freeload_comments ? '`ShiftEntry`.`freeload_comment`, ' : '') . '
@@ -559,10 +521,6 @@ function Shifts_by_user($user, $include_freeload_comments = false)
             $user['UID']
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load users shifts.');
-    }
-    return $result;
 }
 
 /**
@@ -573,22 +531,16 @@ function Shifts_by_user($user, $include_freeload_comments = false)
  */
 function Shift($shift_id)
 {
-    $shifts_source = DB::select('
+    $result = DB::selectOne('
       SELECT `Shifts`.*, `ShiftTypes`.`name`
       FROM `Shifts`
       JOIN `ShiftTypes` ON (`ShiftTypes`.`id` = `Shifts`.`shifttype_id`)
       WHERE `SID`=?', [$shift_id]);
 
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load shift.');
-    }
-
-    if (empty($shifts_source)) {
+    if (empty($result)) {
         return null;
     }
 
-    $result = $shifts_source[0];
-
     $shiftsEntry_source = DB::select('
         SELECT `id`, `TID` , `UID` , `freeloaded`
         FROM `ShiftEntry`
@@ -613,7 +565,7 @@ function Shift($shift_id)
 /**
  * Returns all shifts with needed angeltypes and count of subscribed jobs.
  *
- * @return array|false
+ * @return array
  */
 function Shifts()
 {
@@ -624,10 +576,6 @@ function Shifts()
         JOIN `Room` ON `Room`.`RID` = `Shifts`.`RID`
     ');
 
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
-
     foreach ($shifts_source as &$shift) {
         $needed_angeltypes = NeededAngelTypes_by_shift($shift['SID']);
         $shift['angeltypes'] = $needed_angeltypes;
diff --git a/includes/model/UserAngelTypes_model.php b/includes/model/UserAngelTypes_model.php
index 82f390ee..5b0caf98 100644
--- a/includes/model/UserAngelTypes_model.php
+++ b/includes/model/UserAngelTypes_model.php
@@ -27,23 +27,16 @@ function UserAngelType_exists($user, $angeltype)
  * List users angeltypes.
  *
  * @param array $user
- * @return array|false
+ * @return array
  */
 function User_angeltypes($user)
 {
-    $result = DB::select('
+    return DB::select('
       SELECT `AngelTypes`.*, `UserAngelTypes`.`confirm_user_id`, `UserAngelTypes`.`supporter`
       FROM `UserAngelTypes`
       JOIN `AngelTypes` ON `UserAngelTypes`.`angeltype_id` = `AngelTypes`.`id`
       WHERE `UserAngelTypes`.`user_id`=?
       ', [$user['UID']]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user angeltypes.');
-        return false;
-    }
-
-    return $result;
 }
 
 /**
@@ -54,7 +47,7 @@ function User_angeltypes($user)
  */
 function User_unconfirmed_AngelTypes($user)
 {
-    $result = DB::select('
+    return DB::select('
         SELECT
           `UserAngelTypes`.*,
           `AngelTypes`.`name`,
@@ -69,12 +62,6 @@ function User_unconfirmed_AngelTypes($user)
         GROUP BY `UserAngelTypes`.`angeltype_id`
         ORDER BY `AngelTypes`.`name`
     ', [$user['UID']]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user angeltypes.');
-    }
-
-    return $result;
 }
 
 /**
@@ -110,29 +97,21 @@ function User_is_AngelType_supporter(&$user, $angeltype)
  *
  * @param int  $user_angeltype_id
  * @param bool $supporter
- * @return int
  */
 function UserAngelType_update($user_angeltype_id, $supporter)
 {
-    $result = DB::update('
+    DB::update('
       UPDATE `UserAngelTypes`
       SET `supporter`=?
       WHERE `id`=?
       LIMIT 1
     ', [$supporter, $user_angeltype_id]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to update supporter rights.');
-    }
-
-    return $result;
 }
 
 /**
  * Delete all unconfirmed UserAngelTypes for given Angeltype.
  *
  * @param int $angeltype_id
- * @return bool
  */
 function UserAngelTypes_delete_all($angeltype_id)
 {
@@ -141,12 +120,6 @@ function UserAngelTypes_delete_all($angeltype_id)
       WHERE `angeltype_id`=?
       AND `confirm_user_id` IS NULL
     ', [$angeltype_id]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to delete all unconfirmed users.');
-    }
-
-    return true;
 }
 
 /**
@@ -154,22 +127,15 @@ function UserAngelTypes_delete_all($angeltype_id)
  *
  * @param int   $angeltype_id
  * @param array $confirm_user
- * @return bool
  */
 function UserAngelTypes_confirm_all($angeltype_id, $confirm_user)
 {
-    $result = DB::update('
+    DB::update('
       UPDATE `UserAngelTypes`
       SET `confirm_user_id`=?
       WHERE `angeltype_id`=?
       AND `confirm_user_id` IS NULL
     ', [$confirm_user['UID'], $angeltype_id]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to confirm all users.');
-    }
-
-    return (bool)$result;
 }
 
 /**
@@ -181,26 +147,21 @@ function UserAngelTypes_confirm_all($angeltype_id, $confirm_user)
  */
 function UserAngelType_confirm($user_angeltype_id, $confirm_user)
 {
-    $result = DB::update('
+    DB::update('
       UPDATE `UserAngelTypes`
       SET `confirm_user_id`=?
       WHERE `id`=?
       LIMIT 1', [$confirm_user['UID'], $user_angeltype_id]);
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to confirm user angeltype.');
-    }
-    return (bool)$result;
 }
 
 /**
  * Delete an UserAngelType.
  *
  * @param array $user_angeltype
- * @return bool
  */
 function UserAngelType_delete($user_angeltype)
 {
-    return (bool)DB::delete('
+    DB::delete('
       DELETE FROM `UserAngelTypes`
       WHERE `id`=?
       LIMIT 1', [$user_angeltype['id']]);
@@ -225,10 +186,6 @@ function UserAngelType_create($user, $angeltype)
         ]
     );
 
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to create user angeltype.');
-    }
-
     return DB::getPdo()->lastInsertId();
 }
 
@@ -240,21 +197,11 @@ function UserAngelType_create($user, $angeltype)
  */
 function UserAngelType($user_angeltype_id)
 {
-    $angeltype = DB::select('
+    return DB::selectOne('
       SELECT *
       FROM `UserAngelTypes`
       WHERE `id`=?
       LIMIT 1', [$user_angeltype_id]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user angeltype.');
-    }
-
-    if (empty($angeltype)) {
-        return null;
-    }
-
-    return $angeltype[0];
 }
 
 /**
@@ -266,7 +213,7 @@ function UserAngelType($user_angeltype_id)
  */
 function UserAngelType_by_User_and_AngelType($user, $angeltype)
 {
-    $angeltype = DB::select('
+    return DB::selectOne('
           SELECT *
           FROM `UserAngelTypes`
           WHERE `user_id`=?
@@ -278,14 +225,4 @@ function UserAngelType_by_User_and_AngelType($user, $angeltype)
             $angeltype['id']
         ]
     );
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user angeltype.');
-    }
-
-    if (empty($angeltype)) {
-        return null;
-    }
-
-    return array_shift($angeltype);
 }
diff --git a/includes/model/UserDriverLicenses_model.php b/includes/model/UserDriverLicenses_model.php
index 525d2016..798aa6ab 100644
--- a/includes/model/UserDriverLicenses_model.php
+++ b/includes/model/UserDriverLicenses_model.php
@@ -41,25 +41,14 @@ function UserDriverLicense_valid($user_driver_license)
  * Get a users driver license information
  *
  * @param int $user_id The users id
- * @return array|false|null
+ * @return array|null
  */
 function UserDriverLicense($user_id)
 {
-    $user_driver_license = DB::select('
+    return DB::selectOne('
         SELECT *
         FROM `UserDriverLicenses`
         WHERE `user_id`=?', [$user_id]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user driver license.');
-        return false;
-    }
-
-    if (empty($user_driver_license)) {
-        return null;
-    }
-
-    return array_shift($user_driver_license);
 }
 
 /**
@@ -94,9 +83,6 @@ function UserDriverLicenses_create($user_driver_license, $user)
             (bool)$user_driver_license['has_license_forklift'],
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to create user driver license');
-    }
 
     return $user_driver_license;
 }
@@ -105,11 +91,10 @@ function UserDriverLicenses_create($user_driver_license, $user)
  * Update a user's driver license entry
  *
  * @param array $user_driver_license The UserDriverLicense to update
- * @return bool
  */
 function UserDriverLicenses_update($user_driver_license)
 {
-    $result = DB::update('
+    DB::update('
           UPDATE `UserDriverLicenses`
           SET
               `has_car`=?,
@@ -130,23 +115,14 @@ function UserDriverLicenses_update($user_driver_license)
             $user_driver_license['user_id'],
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to update user driver license information');
-    }
-    return $result;
 }
 
 /**
  * Delete a user's driver license entry
  *
  * @param int $user_id
- * @return bool
  */
 function UserDriverLicenses_delete($user_id)
 {
-    $result = DB::delete('DELETE FROM `UserDriverLicenses` WHERE `user_id`=?', [$user_id]);
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to remove user driver license information');
-    }
-    return $result;
+    DB::delete('DELETE FROM `UserDriverLicenses` WHERE `user_id`=?', [$user_id]);
 }
diff --git a/includes/model/User_model.php b/includes/model/User_model.php
index 2913c1a1..4757ed3c 100644
--- a/includes/model/User_model.php
+++ b/includes/model/User_model.php
@@ -11,24 +11,20 @@ use Engelsystem\ValidationResult;
  * Delete a user
  *
  * @param int $user_id
- * @return bool
  */
 function User_delete($user_id)
 {
     DB::delete('DELETE FROM `User` WHERE `UID`=?', [$user_id]);
-
-    return DB::getStm()->errorCode() == '00000';
 }
 
 /**
  * Update user.
  *
  * @param array $user
- * @return bool
  */
 function User_update($user)
 {
-    return (bool)DB::update('
+    DB::update('
           UPDATE `User` SET
           `Nick`=?,
           `Name`=?,
@@ -91,8 +87,7 @@ function User_update($user)
  */
 function User_force_active_count()
 {
-    $result = DB::select('SELECT COUNT(*) FROM `User` WHERE `force_active` = 1');
-    $result = array_shift($result);
+    $result = DB::selectOne('SELECT COUNT(*) FROM `User` WHERE `force_active` = 1');
 
     if (empty($result)) {
         return 0;
@@ -106,8 +101,7 @@ function User_force_active_count()
  */
 function User_active_count()
 {
-    $result = DB::select('SELECT COUNT(*) FROM `User` WHERE `Aktiv` = 1');
-    $result = array_shift($result);
+    $result = DB::selectOne('SELECT COUNT(*) FROM `User` WHERE `Aktiv` = 1');
 
     if (empty($result)) {
         return 0;
@@ -121,8 +115,7 @@ function User_active_count()
  */
 function User_got_voucher_count()
 {
-    $result = DB::select('SELECT SUM(`got_voucher`) FROM `User`');
-    $result = array_shift($result);
+    $result = DB::selectOne('SELECT SUM(`got_voucher`) FROM `User`');
 
     if (empty($result)) {
         return 0;
@@ -136,8 +129,7 @@ function User_got_voucher_count()
  */
 function User_arrived_count()
 {
-    $result = DB::select('SELECT COUNT(*) FROM `User` WHERE `Gekommen` = 1');
-    $result = array_shift($result);
+    $result = DB::selectOne('SELECT COUNT(*) FROM `User` WHERE `Gekommen` = 1');
 
     if (empty($result)) {
         return 0;
@@ -151,8 +143,7 @@ function User_arrived_count()
  */
 function User_tshirts_count()
 {
-    $result = DB::select('SELECT COUNT(*) FROM `User` WHERE `Tshirt` = 1');
-    $result = array_shift($result);
+    $result = DB::selectOne('SELECT COUNT(*) FROM `User` WHERE `Tshirt` = 1');
 
     if (empty($result)) {
         return 0;
@@ -188,23 +179,17 @@ function User_sortable_columns()
  * Get all users, ordered by Nick by default or by given param.
  *
  * @param string $order_by
- * @return array|false
+ * @return array
  */
 function Users($order_by = 'Nick')
 {
-    $result = DB::select(sprintf('
+    return DB::select(sprintf('
             SELECT *
             FROM `User`
             ORDER BY `%s` ASC
         ',
         trim(DB::getPdo()->quote($order_by), '\'')
     ));
-
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
-
-    return $result;
 }
 
 /**
@@ -228,7 +213,7 @@ function User_is_freeloader($user)
  */
 function Users_by_angeltype_inverted($angeltype)
 {
-    $result = DB::select('
+    return DB::select('
             SELECT `User`.*
             FROM `User`
             LEFT JOIN `UserAngelTypes`
@@ -240,10 +225,6 @@ function Users_by_angeltype_inverted($angeltype)
             $angeltype['id']
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load users.');
-    }
-    return $result;
 }
 
 /**
@@ -254,12 +235,13 @@ function Users_by_angeltype_inverted($angeltype)
  */
 function Users_by_angeltype($angeltype)
 {
-    $result = DB::select('
+    return DB::select('
             SELECT
             `User`.*,
             `UserAngelTypes`.`id` AS `user_angeltype_id`,
             `UserAngelTypes`.`confirm_user_id`,
             `UserAngelTypes`.`supporter`,
+            (`UserDriverLicenses`.`user_id` IS NOT NULL) as `wants_to_drive`,
             `UserDriverLicenses`.*
             FROM `User`
             JOIN `UserAngelTypes` ON `User`.`UID`=`UserAngelTypes`.`user_id`
@@ -271,10 +253,6 @@ function Users_by_angeltype($angeltype)
             $angeltype['id']
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load members.');
-    }
-    return $result;
 }
 
 /**
@@ -399,17 +377,7 @@ function User_validate_planned_departure_date($planned_arrival_date, $planned_de
  */
 function User($user_id)
 {
-    $user_source = DB::select('SELECT * FROM `User` WHERE `UID`=? LIMIT 1', [$user_id]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user.');
-    }
-
-    if (empty($user_source)) {
-        return null;
-    }
-
-    return array_shift($user_source);
+    return DB::selectOne('SELECT * FROM `User` WHERE `UID`=? LIMIT 1', [$user_id]);
 }
 
 /**
@@ -417,21 +385,11 @@ function User($user_id)
  *
  * @param string $api_key
  *          User api key
- * @return array|null Matching user, null on error
+ * @return array|null Matching user, null if not found
  */
 function User_by_api_key($api_key)
 {
-    $user = DB::select('SELECT * FROM `User` WHERE `api_key`=? LIMIT 1', [$api_key]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to find user by api key.');
-    }
-
-    if (empty($user)) {
-        return null;
-    }
-
-    return $user[0];
+    return DB::selectOne('SELECT * FROM `User` WHERE `api_key`=? LIMIT 1', [$api_key]);
 }
 
 /**
@@ -442,38 +400,18 @@ function User_by_api_key($api_key)
  */
 function User_by_email($email)
 {
-    $user = DB::select('SELECT * FROM `User` WHERE `email`=? LIMIT 1', [$email]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user.');
-    }
-
-    if (empty($user)) {
-        return null;
-    }
-
-    return array_shift($user);
+    return DB::selectOne('SELECT * FROM `User` WHERE `email`=? LIMIT 1', [$email]);
 }
 
 /**
  * Returns User by password token.
  *
  * @param string $token
- * @return array|null Matching user, null or false on error
+ * @return array|null Matching user, null when not found
  */
 function User_by_password_recovery_token($token)
 {
-    $user = DB::select('SELECT * FROM `User` WHERE `password_recovery_token`=? LIMIT 1', [$token]);
-
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to load user.');
-    }
-
-    if (empty($user)) {
-        return null;
-    }
-
-    return array_shift($user);
+    return DB::selectOne('SELECT * FROM `User` WHERE `password_recovery_token`=? LIMIT 1', [$token]);
 }
 
 /**
@@ -481,7 +419,6 @@ function User_by_password_recovery_token($token)
  *
  * @param array $user
  * @param bool  $log
- * @return bool
  */
 function User_reset_api_key(&$user, $log = true)
 {
@@ -497,15 +434,10 @@ function User_reset_api_key(&$user, $log = true)
             $user['UID']
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        return false;
-    }
 
     if ($log) {
         engelsystem_log(sprintf('API key resetted (%s).', User_Nick_render($user)));
     }
-
-    return true;
 }
 
 /**
@@ -528,9 +460,6 @@ function User_generate_password_recovery_token(&$user)
             $user['UID'],
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to generate password recovery token.');
-    }
     engelsystem_log('Password recovery for ' . User_Nick_render($user) . ' started.');
     return $user['password_recovery_token'];
 }
diff --git a/includes/pages/admin_active.php b/includes/pages/admin_active.php
index 5b91e413..d67af681 100644
--- a/includes/pages/admin_active.php
+++ b/includes/pages/admin_active.php
@@ -232,19 +232,17 @@ function admin_active()
     $shirt_statistics = [];
     foreach (array_keys($tshirt_sizes) as $size) {
         if (!empty($size)) {
-            $sc = DB::select(
+            $sc = DB::selectOne(
                 'SELECT count(*) FROM `User` WHERE `Size`=? AND `Gekommen`=1',
                 [$size]
             );
             $sc = array_shift($sc);
-            $sc = array_shift($sc);
 
-            $gc = DB::select(
+            $gc = DB::selectOne(
                 'SELECT count(*) FROM `User` WHERE `Size`=? AND `Tshirt`=1',
                 [$size]
             );
             $gc = array_shift($gc);
-            $gc = array_shift($gc);
 
             $shirt_statistics[] = [
                 'size'   => $size,
@@ -254,8 +252,7 @@ function admin_active()
         }
     }
 
-    $uc = DB::select('SELECT count(*) FROM `User` WHERE `Tshirt`=1');
-    $uc = array_shift($uc);
+    $uc = DB::selectOne('SELECT count(*) FROM `User` WHERE `Tshirt`=1');
     $uc = array_shift($uc);
 
     $shirt_statistics[] = [
diff --git a/includes/pages/admin_groups.php b/includes/pages/admin_groups.php
index 1de8bfb7..e0260320 100644
--- a/includes/pages/admin_groups.php
+++ b/includes/pages/admin_groups.php
@@ -112,23 +112,21 @@ function admin_groups()
                     return error('Incomplete call, missing Groups ID.', true);
                 }
 
-                $group = DB::select('SELECT * FROM `Groups` WHERE `UID`=? LIMIT 1', [$group_id]);
+                $group = DB::selectOne('SELECT * FROM `Groups` WHERE `UID`=? LIMIT 1', [$group_id]);
                 $privileges = $request->postData('privileges');
                 if (!is_array($privileges)) {
                     $privileges = [];
                 }
                 if (!empty($group)) {
-                    $group = array_shift($group);
                     DB::delete('DELETE FROM `GroupPrivileges` WHERE `group_id`=?', [$group_id]);
                     $privilege_names = [];
                     foreach ($privileges as $privilege) {
                         if (preg_match('/^\d{1,}$/', $privilege)) {
-                            $group_privileges_source = DB::select(
+                            $group_privileges_source = DB::selectOne(
                                 'SELECT `name` FROM `Privileges` WHERE `id`=? LIMIT 1',
                                 [$privilege]
                             );
                             if (!empty($group_privileges_source)) {
-                                $group_privileges_source = array_shift($group_privileges_source);
                                 DB::insert(
                                     'INSERT INTO `GroupPrivileges` (`group_id`, `privilege_id`) VALUES (?, ?)',
                                     [$group_id, $privilege]
diff --git a/includes/pages/admin_import.php b/includes/pages/admin_import.php
index 3cbed9f9..bda5ba93 100644
--- a/includes/pages/admin_import.php
+++ b/includes/pages/admin_import.php
@@ -45,9 +45,6 @@ function admin_import()
     $add_minutes_end = 15;
 
     $shifttypes_source = ShiftTypes();
-    if ($shifttypes_source === false) {
-        engelsystem_error('Unable to load shifttypes.');
-    }
     $shifttypes = [];
     foreach ($shifttypes_source as $shifttype) {
         $shifttypes[$shifttype['id']] = $shifttype['name'];
@@ -251,9 +248,7 @@ function admin_import()
             list($rooms_new, $rooms_deleted) = prepare_rooms($import_file);
             foreach ($rooms_new as $room) {
                 $result = Room_create($room, true, true);
-                if ($result === false) {
-                    engelsystem_error('Unable to create room.');
-                }
+                
                 $rooms_import[trim($room)] = $result;
             }
             foreach ($rooms_deleted as $room) {
@@ -267,24 +262,15 @@ function admin_import()
                 $add_minutes_end
             );
             foreach ($events_new as $event) {
-                $result = Shift_create($event);
-                if ($result === false) {
-                    engelsystem_error('Unable to create shift.');
-                }
+                Shift_create($event);
             }
 
             foreach ($events_updated as $event) {
-                $result = Shift_update_by_psid($event);
-                if ($result === false) {
-                    engelsystem_error('Unable to update shift.');
-                }
+                Shift_update_by_psid($event);
             }
 
             foreach ($events_deleted as $event) {
-                $result = Shift_delete_by_psid($event['PSID']);
-                if ($result === false) {
-                    engelsystem_error('Unable to delete shift.');
-                }
+                Shift_delete_by_psid($event['PSID']);
             }
 
             engelsystem_log('Frab import done');
diff --git a/includes/pages/admin_news.php b/includes/pages/admin_news.php
index bc78a6b1..eb3a250e 100644
--- a/includes/pages/admin_news.php
+++ b/includes/pages/admin_news.php
@@ -21,14 +21,13 @@ function admin_news()
         return error('Incomplete call, missing News ID.', true);
     }
 
-    $news = DB::select('SELECT * FROM `News` WHERE `ID`=? LIMIT 1', [$news_id]);
+    $news = DB::selectOne('SELECT * FROM `News` WHERE `ID`=? LIMIT 1', [$news_id]);
     if (empty($news)) {
         return error('No News found.', true);
     }
 
     switch ($request->input('action')) {
         case 'edit':
-            $news = array_shift($news);
             $user_source = User($news['UID']);
 
             $html .= form(
@@ -81,7 +80,6 @@ function admin_news()
             break;
 
         case 'delete':
-            $news = array_shift($news);
             DB::delete('DELETE FROM `News` WHERE `ID`=? LIMIT 1', [$news_id]);
             engelsystem_log('News deleted: ' . $news['Betreff']);
             success(_('News entry deleted.'));
diff --git a/includes/pages/admin_questions.php b/includes/pages/admin_questions.php
index 938e63a9..5f2e3a2b 100644
--- a/includes/pages/admin_questions.php
+++ b/includes/pages/admin_questions.php
@@ -105,11 +105,11 @@ function admin_questions()
                     return error('Incomplete call, missing Question ID.', true);
                 }
 
-                $question = DB::select(
+                $question = DB::selectOne(
                     'SELECT * FROM `Questions` WHERE `QID`=? LIMIT 1',
                     [$question_id]
                 );
-                if (count($question) > 0 && $question[0]['AID'] == null) {
+                if (!empty($question) && $question['AID'] == null) {
                     $answer = trim(
                         preg_replace("/([^\p{L}\p{P}\p{Z}\p{N}\n]{1,})/ui",
                             '',
@@ -129,7 +129,7 @@ function admin_questions()
                                 $question_id,
                             ]
                         );
-                        engelsystem_log('Question ' . $question[0]['Question'] . ' answered: ' . $answer);
+                        engelsystem_log('Question ' . $question['Question'] . ' answered: ' . $answer);
                         redirect(page_link_to('admin_questions'));
                     } else {
                         return error('Enter an answer!', true);
@@ -145,13 +145,13 @@ function admin_questions()
                     return error('Incomplete call, missing Question ID.', true);
                 }
 
-                $question = DB::select(
+                $question = DB::selectOne(
                     'SELECT * FROM `Questions` WHERE `QID`=? LIMIT 1',
                     [$question_id]
                 );
-                if (count($question) > 0) {
+                if (!empty($question)) {
                     DB::delete('DELETE FROM `Questions` WHERE `QID`=? LIMIT 1', [$question_id]);
-                    engelsystem_log('Question deleted: ' . $question[0]['Question']);
+                    engelsystem_log('Question deleted: ' . $question['Question']);
                     redirect(page_link_to('admin_questions'));
                 } else {
                     return error('No question found.', true);
diff --git a/includes/pages/admin_rooms.php b/includes/pages/admin_rooms.php
index 457114a0..9e153bf1 100644
--- a/includes/pages/admin_rooms.php
+++ b/includes/pages/admin_rooms.php
@@ -22,8 +22,8 @@ function admin_rooms()
     foreach ($rooms_source as $room) {
         $rooms[] = [
             'name'           => Room_name_render($room),
-            'from_pentabarf' => $room['FromPentabarf'] == 'Y' ? '✓' : '',
-            'public'         => $room['show'] == 'Y' ? '✓' : '',
+            'from_pentabarf' => glyph_bool($room['FromPentabarf'] == 'Y'),
+            'public'         => glyph_bool($room['show'] == 'Y'),
             'actions'        => table_buttons([
                 button(page_link_to('admin_rooms', ['show' => 'edit', 'id' => $room['RID']]), _('edit'), 'btn-xs'),
                 button(page_link_to('admin_rooms', ['show' => 'delete', 'id' => $room['RID']]), _('delete'), 'btn-xs')
@@ -50,9 +50,6 @@ function admin_rooms()
 
         if (test_request_int('id')) {
             $room = Room($request->input('id'), false);
-            if ($room === false) {
-                engelsystem_error('Unable to load room.');
-            }
             if ($room == null) {
                 redirect(page_link_to('admin_rooms'));
             }
@@ -150,9 +147,7 @@ function admin_rooms()
                         );
                     } else {
                         $room_id = Room_create($name, $from_pentabarf, $public, $number);
-                        if ($room_id === false) {
-                            engelsystem_error('Unable to create room.');
-                        }
+
                         engelsystem_log(
                             'Room created: ' . $name
                             . ', pentabarf import: '
@@ -214,9 +209,7 @@ function admin_rooms()
             ]);
         } elseif ($request->input('show') == 'delete') {
             if ($request->has('ack')) {
-                if (!Room_delete($room_id)) {
-                    engelsystem_error('Unable to delete room.');
-                }
+                Room_delete($room_id);
 
                 engelsystem_log('Room deleted: ' . $name);
                 success(sprintf(_('Room %s deleted.'), $name));
diff --git a/includes/pages/admin_shifts.php b/includes/pages/admin_shifts.php
index d36635f7..04d88a4f 100644
--- a/includes/pages/admin_shifts.php
+++ b/includes/pages/admin_shifts.php
@@ -44,9 +44,6 @@ function admin_shifts()
 
     // Load shift types
     $shifttypes_source = ShiftTypes();
-    if ($shifttypes_source === false) {
-        engelsystem_error('Unable to load shift types.');
-    }
     $shifttypes = [];
     foreach ($shifttypes_source as $shifttype) {
         $shifttypes[$shifttype['id']] = $shifttype['name'];
@@ -317,9 +314,6 @@ function admin_shifts()
             $shift['URL'] = null;
             $shift['PSID'] = null;
             $shift_id = Shift_create($shift);
-            if ($shift_id === false) {
-                engelsystem_error('Unable to create shift.');
-            }
 
             engelsystem_log(
                 'Shift created: ' . $shifttypes[$shift['shifttype_id']]
@@ -329,7 +323,7 @@ function admin_shifts()
             );
 
             foreach ($_SESSION['admin_shifts_types'] as $type_id => $count) {
-                $angel_type_source = DB::select('
+                $angel_type_source = DB::selectOne('
                       SELECT *
                       FROM `AngelTypes`
                       WHERE `id` = ?
@@ -345,7 +339,7 @@ function admin_shifts()
                             $count
                         ]
                     );
-                    $needed_angel_types_info[] = $angel_type_source[0]['name'] . ': ' . $count;
+                    $needed_angel_types_info[] = $angel_type_source['name'] . ': ' . $count;
                 }
             }
         }
diff --git a/includes/pages/admin_user.php b/includes/pages/admin_user.php
index ca814b2e..9b3b0f44 100644
--- a/includes/pages/admin_user.php
+++ b/includes/pages/admin_user.php
@@ -119,20 +119,20 @@ function admin_user()
 
         $html .= '<hr />';
 
-        $my_highest_group = DB::select(
+        $my_highest_group = DB::selectOne(
             'SELECT group_id FROM `UserGroups` WHERE `uid`=? ORDER BY `group_id` LIMIT 1',
             [$user['UID']]
         );
-        if (count($my_highest_group) > 0) {
-            $my_highest_group = $my_highest_group[0]['group_id'];
+        if (!empty($my_highest_group)) {
+            $my_highest_group = $my_highest_group['group_id'];
         }
 
-        $his_highest_group = DB::select(
+        $his_highest_group = DB::selectOne(
             'SELECT `group_id` FROM `UserGroups` WHERE `uid`=? ORDER BY `group_id` LIMIT 1',
             [$user_id]
         );
-        if (count($his_highest_group) > 0) {
-            $his_highest_group = $his_highest_group[0]['group_id'];
+        if (!empty($his_highest_group)) {
+            $his_highest_group = $his_highest_group['group_id'];
         }
 
         if ($user_id != $user['UID'] && $my_highest_group <= $his_highest_group) {
@@ -192,7 +192,7 @@ function admin_user()
                         count($my_highest_group) > 0
                         && (
                             count($his_highest_group) == 0
-                            || ($my_highest_group[0]['group_id'] <= $his_highest_group[0]['group_id'])
+                            || ($my_highest_group['group_id'] <= $his_highest_group['group_id'])
                         )
                     ) {
                         $groups_source = DB::select('
@@ -207,7 +207,7 @@ function admin_user()
                             ',
                             [
                                 $user_id,
-                                $my_highest_group[0]['group_id'],
+                                $my_highest_group['group_id'],
                             ]
                         );
                         $groups = [];
diff --git a/includes/pages/guest_login.php b/includes/pages/guest_login.php
index 9c706cfc..4a77b40c 100644
--- a/includes/pages/guest_login.php
+++ b/includes/pages/guest_login.php
@@ -399,9 +399,8 @@ function guest_login()
     if ($request->has('submit')) {
         if ($request->has('nick') && strlen(User_validate_Nick($request->input('nick'))) > 0) {
             $nick = User_validate_Nick($request->input('nick'));
-            $login_user = DB::select('SELECT * FROM `User` WHERE `Nick`=?', [$nick]);
-            if (count($login_user) > 0) {
-                $login_user = $login_user[0];
+            $login_user = DB::selectOne('SELECT * FROM `User` WHERE `Nick`=?', [$nick]);
+            if (!empty($login_user)) {
                 if ($request->has('password')) {
                     if (!verify_password($request->postData('password'), $login_user['Passwort'], $login_user['UID'])) {
                         $valid = false;
diff --git a/includes/pages/guest_stats.php b/includes/pages/guest_stats.php
index 8aa6f740..bf1814a3 100644
--- a/includes/pages/guest_stats.php
+++ b/includes/pages/guest_stats.php
@@ -17,13 +17,12 @@ function guest_stats()
             list($arrived_user_count) = DB::select('SELECT count(*) AS `user_count` FROM `User` WHERE `Gekommen`=1');
             $stats['arrived_user_count'] = $arrived_user_count['user_count'];
 
-            $done_shifts_seconds = DB::select('
+            $done_shifts_seconds = DB::selectOne('
                 SELECT SUM(`Shifts`.`end` - `Shifts`.`start`)
                 FROM `ShiftEntry`
                 JOIN `Shifts` USING (`SID`)
                 WHERE `Shifts`.`end` < UNIX_TIMESTAMP()
             ');
-            $done_shifts_seconds = array_shift($done_shifts_seconds);
             $done_shifts_seconds = (int)array_shift($done_shifts_seconds);
             $stats['done_work_hours'] = round($done_shifts_seconds / (60 * 60), 0);
 
diff --git a/includes/pages/user_messages.php b/includes/pages/user_messages.php
index 320af9df..06ae7e75 100644
--- a/includes/pages/user_messages.php
+++ b/includes/pages/user_messages.php
@@ -130,11 +130,11 @@ function user_messages()
                     return error(_('Incomplete call, missing Message ID.'), true);
                 }
 
-                $message = DB::select(
+                $message = DB::selectOne(
                     'SELECT `RUID` FROM `Messages` WHERE `id`=? LIMIT 1',
                     [$message_id]
                 );
-                if (count($message) > 0 && $message[0]['RUID'] == $user['UID']) {
+                if (!empty($message) && $message['RUID'] == $user['UID']) {
                     DB::update(
                         'UPDATE `Messages` SET `isRead`=\'Y\' WHERE `id`=? LIMIT 1',
                         [$message_id]
@@ -152,11 +152,11 @@ function user_messages()
                     return error(_('Incomplete call, missing Message ID.'), true);
                 }
 
-                $message = DB::select(
+                $message = DB::selectOne(
                     'SELECT `SUID` FROM `Messages` WHERE `id`=? LIMIT 1',
                     [$message_id]
                 );
-                if (count($message) > 0 && $message[0]['SUID'] == $user['UID']) {
+                if (!empty($message) && $message['SUID'] == $user['UID']) {
                     DB::delete('DELETE FROM `Messages` WHERE `id`=? LIMIT 1', [$message_id]);
                     redirect(page_link_to('user_messages'));
                 } else {
diff --git a/includes/pages/user_myshifts.php b/includes/pages/user_myshifts.php
index 572b777a..60a26922 100644
--- a/includes/pages/user_myshifts.php
+++ b/includes/pages/user_myshifts.php
@@ -31,8 +31,7 @@ function user_myshifts()
         $user_id = $user['UID'];
     }
 
-    $shifts_user = DB::select('SELECT * FROM `User` WHERE `UID`=? LIMIT 1', [$user_id]);
-    $shifts_user = array_shift($shifts_user);
+    $shifts_user = DB::selectOne('SELECT * FROM `User` WHERE `UID`=? LIMIT 1', [$user_id]);
 
     if ($request->has('reset')) {
         if ($request->input('reset') == 'ack') {
@@ -49,7 +48,7 @@ function user_myshifts()
         ]);
     } elseif ($request->has('edit') && preg_match('/^\d*$/', $request->input('edit'))) {
         $user_id = $request->input('edit');
-        $shift = DB::select('
+        $shift = DB::selectOne('
                 SELECT
                     `ShiftEntry`.`freeloaded`,
                     `ShiftEntry`.`freeload_comment`,
@@ -74,7 +73,6 @@ function user_myshifts()
             ]
         );
         if (count($shift) > 0) {
-            $shift = array_shift($shift);
             $freeloaded = $shift['freeloaded'];
             $freeload_comment = $shift['freeload_comment'];
 
@@ -93,15 +91,12 @@ function user_myshifts()
                 $user_source = User($shift['UID']);
 
                 if ($valid) {
-                    $result = ShiftEntry_update([
+                    ShiftEntry_update([
                         'id'               => $user_id,
                         'Comment'          => $comment,
                         'freeloaded'       => $freeloaded,
                         'freeload_comment' => $freeload_comment
                     ]);
-                    if ($result === false) {
-                        engelsystem_error('Unable to update shift entry.');
-                    }
 
                     engelsystem_log(
                         'Updated ' . User_Nick_render($user_source) . '\'s shift ' . $shift['name']
@@ -131,7 +126,7 @@ function user_myshifts()
         }
     } elseif ($request->has('cancel') && preg_match('/^\d*$/', $request->input('cancel'))) {
         $user_id = $request->input('cancel');
-        $shift = DB::select('
+        $shift = DB::selectOne('
                 SELECT *
                 FROM `Shifts`
                 INNER JOIN `ShiftEntry` USING (`SID`)
@@ -143,15 +138,12 @@ function user_myshifts()
             ]
         );
         if (count($shift) > 0) {
-            $shift = array_shift($shift);
             if (
                 ($shift['start'] > time() + config('last_unsubscribe') * 3600)
                 || in_array('user_shifts_admin', $privileges)
             ) {
-                $result = ShiftEntry_delete($user_id);
-                if ($result === false) {
-                    engelsystem_error('Unable to delete shift entry.');
-                }
+                ShiftEntry_delete($user_id);
+
                 $room = Room($shift['RID']);
                 $angeltype = AngelType($shift['TID']);
                 $shifttype = ShiftType($shift['shifttype_id']);
diff --git a/includes/pages/user_news.php b/includes/pages/user_news.php
index 0e38e619..b51b0a4c 100644
--- a/includes/pages/user_news.php
+++ b/includes/pages/user_news.php
@@ -126,8 +126,7 @@ function user_news_comments()
         && count(DB::select('SELECT `ID` FROM `News` WHERE `ID`=? LIMIT 1', [$request->input('nid')])) > 0
     ) {
         $nid = $request->input('nid');
-        $news = DB::select('SELECT * FROM `News` WHERE `ID`=? LIMIT 1', [$nid]);
-        $news = array_shift($news);
+        $news = DB::selectOne('SELECT * FROM `News` WHERE `ID`=? LIMIT 1', [$nid]);
         if ($request->has('text')) {
             $text = preg_replace("/([^\p{L}\p{P}\p{Z}\p{N}\n]{1,})/ui", '', strip_tags($request->input('text')));
             DB::insert('
diff --git a/includes/pages/user_questions.php b/includes/pages/user_questions.php
index 20f82eb1..41fbe64d 100644
--- a/includes/pages/user_questions.php
+++ b/includes/pages/user_questions.php
@@ -43,15 +43,13 @@ function user_questions()
             case 'ask':
                 $question = strip_request_item_nl('question');
                 if ($question != '') {
-                    $result = DB::insert('
+                    DB::insert('
                         INSERT INTO `Questions` (`UID`, `Question`)
                         VALUES (?, ?)
                         ',
                         [$user['UID'], $question]
                     );
-                    if (!$result) {
-                        engelsystem_error(_('Unable to save question.'));
-                    }
+
                     success(_('You question was saved.'));
                     redirect(page_link_to('user_questions'));
                 } else {
@@ -67,11 +65,11 @@ function user_questions()
                     return error(_('Incomplete call, missing Question ID.'), true);
                 }
 
-                $question = DB::select(
+                $question = DB::selectOne(
                     'SELECT `UID` FROM `Questions` WHERE `QID`=? LIMIT 1',
                     [$question_id]
                 );
-                if (count($question) > 0 && $question[0]['UID'] == $user['UID']) {
+                if (!empty($question) && $question['UID'] == $user['UID']) {
                     DB::delete(
                         'DELETE FROM `Questions` WHERE `QID`=? LIMIT 1',
                         [$question_id]
diff --git a/includes/pages/user_settings.php b/includes/pages/user_settings.php
index 9a43f5ce..03621a45 100644
--- a/includes/pages/user_settings.php
+++ b/includes/pages/user_settings.php
@@ -84,6 +84,7 @@ function user_settings_main($user_source, $enable_tshirt_size, $tshirt_sizes)
 
     if ($valid) {
         User_update($user_source);
+
         success(_('Settings saved.'));
         redirect(page_link_to('user_settings'));
     }
@@ -108,10 +109,9 @@ function user_settings_password($user_source)
         error(_('Your password is to short (please use at least 6 characters).'));
     } elseif ($request->postData('new_password') != $request->postData('new_password2')) {
         error(_('Your passwords don\'t match.'));
-    } elseif (set_password($user_source['UID'], $request->postData('new_password'))) {
-        success(_('Password saved.'));
     } else {
-        error(_('Failed setting password.'));
+        set_password($user_source['UID'], $request->postData('new_password'));
+        success(_('Password saved.'));
     }
     redirect(page_link_to('user_settings'));
 }
diff --git a/includes/sys_auth.php b/includes/sys_auth.php
index 607d180b..36f0f935 100644
--- a/includes/sys_auth.php
+++ b/includes/sys_auth.php
@@ -11,10 +11,9 @@ function load_auth()
 
     $user = null;
     if (isset($_SESSION['uid'])) {
-        $user = DB::select('SELECT * FROM `User` WHERE `UID`=? LIMIT 1', [$_SESSION['uid']]);
-        if (count($user) > 0) {
+        $user = DB::selectOne('SELECT * FROM `User` WHERE `UID`=? LIMIT 1', [$_SESSION['uid']]);
+        if (!empty($user)) {
             // User ist eingeloggt, Datensatz zur Verfügung stellen und Timestamp updaten
-            $user = array_shift($user);
             DB::update('
                 UPDATE `User`
                 SET `lastLogIn` = ?
@@ -55,11 +54,10 @@ function generate_salt($length = 16)
  *
  * @param int    $uid
  * @param string $password
- * @return bool
  */
 function set_password($uid, $password)
 {
-    $result = DB::update('
+    DB::update('
         UPDATE `User`
         SET `Passwort` = ?,
         `password_recovery_token`=NULL
@@ -71,10 +69,6 @@ function set_password($uid, $password)
             $uid
         ]
     );
-    if (DB::getStm()->errorCode() != '00000') {
-        engelsystem_error('Unable to update password.');
-    }
-    return $result;
 }
 
 /**
diff --git a/includes/sys_form.php b/includes/sys_form.php
index 148af965..7fa0682d 100644
--- a/includes/sys_form.php
+++ b/includes/sys_form.php
@@ -411,7 +411,7 @@ function html_select_key($dom_id, $name, $rows, $selected)
 {
     $html = '<select class="form-control" id="' . $dom_id . '" name="' . $name . '">';
     foreach ($rows as $key => $row) {
-        if (($key == $selected) || ($row == $selected)) {
+        if (($key == $selected) || ($row === $selected)) {
             $html .= '<option value="' . $key . '" selected="selected">' . $row . '</option>';
         } else {
             $html .= '<option value="' . $key . '">' . $row . '</option>';
diff --git a/includes/view/AngelTypes_view.php b/includes/view/AngelTypes_view.php
index 32f58d4b..f75cc616 100644
--- a/includes/view/AngelTypes_view.php
+++ b/includes/view/AngelTypes_view.php
@@ -184,7 +184,6 @@ function AngelType_view_members($angeltype, $members, $admin_user_angeltypes, $a
     $members_unconfirmed = [];
     foreach ($members as $member) {
         $member['Nick'] = User_Nick_render($member);
-
         if ($angeltype['requires_driver_license']) {
             $member['wants_to_drive'] = glyph_bool($member['wants_to_drive']);
             $member['has_car'] = glyph_bool($member['has_car']);
diff --git a/includes/view/ShiftCalendarLane.php b/includes/view/ShiftCalendarLane.php
index 774683bd..fd4c6f06 100644
--- a/includes/view/ShiftCalendarLane.php
+++ b/includes/view/ShiftCalendarLane.php
@@ -2,6 +2,8 @@
 
 namespace Engelsystem;
 
+use Exception;
+
 /**
  * Represents a single lane in a shifts calendar.
  */
@@ -38,15 +40,15 @@ class ShiftCalendarLane
      * Returns true on success.
      *
      * @param array $shift The shift to add
-     * @return boolean true on success
+     * @throws Exception if the shift doesn't fit into the lane.
      */
     public function addShift($shift)
     {
         if ($this->shiftFits($shift)) {
             $this->shifts[] = $shift;
-            return true;
+            return;
         }
-        return false;
+        throw new Exception('Unable to add shift to shift calendar lane.');
     }
 
     /**
diff --git a/includes/view/ShiftCalendarRenderer.php b/includes/view/ShiftCalendarRenderer.php
index aad0d643..3269f338 100644
--- a/includes/view/ShiftCalendarRenderer.php
+++ b/includes/view/ShiftCalendarRenderer.php
@@ -1,9 +1,11 @@
 <?php
-
 namespace Engelsystem;
 
+use Exception;
+
 class ShiftCalendarRenderer
 {
+
     /**
      * 15m * 60s/m = 900s
      */
@@ -49,10 +51,10 @@ class ShiftCalendarRenderer
     /**
      * ShiftCalendarRenderer constructor.
      *
-     * @param array[]      $shifts
-     * @param array[]      $needed_angeltypes
-     * @param array[]      $shift_entries
-     * @param ShiftsFilter $shiftsFilter
+     * @param array[] $shifts            
+     * @param array[] $needed_angeltypes            
+     * @param array[] $shift_entries            
+     * @param ShiftsFilter $shiftsFilter            
      */
     public function __construct($shifts, $needed_angeltypes, $shift_entries, ShiftsFilter $shiftsFilter)
     {
@@ -67,22 +69,23 @@ class ShiftCalendarRenderer
     /**
      * Assigns the shifts to different lanes per room if they collide
      *
-     * @param array[] $shifts The shifts to assign
-     *
+     * @param array[] $shifts
+     *            The shifts to assign
+     *            
      * @return array Returns an array that assigns a room_id to an array of ShiftCalendarLane containing the shifts
      */
     private function assignShiftsToLanes($shifts)
     {
         // array that assigns a room id to a list of lanes (per room)
         $lanes = [];
-
+        
         foreach ($shifts as $shift) {
             $room_id = $shift['RID'];
             $header = Room_name_render([
-                'RID'  => $room_id,
+                'RID' => $room_id,
                 'Name' => $shift['room_name']
             ]);
-            if (!isset($lanes[$room_id])) {
+            if (! isset($lanes[$room_id])) {
                 // initialize room with one lane
                 $lanes[$room_id] = [
                     new ShiftCalendarLane($header, $this->getFirstBlockStartTime(), $this->getBlocksPerSlot())
@@ -92,25 +95,25 @@ class ShiftCalendarRenderer
             $shift_added = false;
             foreach ($lanes[$room_id] as $lane) {
                 /** @var ShiftCalendarLane $lane */
-                $shift_added = $lane->addShift($shift);
-                if ($shift_added == true) {
+                if($lane->shiftFits($shift)) {
+                    $lane->addShift($shift);
+                    $shift_added = true;
                     break;
                 }
             }
             // If all lanes for this room are busy, create a new lane and add shift to it
             if ($shift_added == false) {
                 $newLane = new ShiftCalendarLane($header, $this->getFirstBlockStartTime(), $this->getBlocksPerSlot());
-                if (!$newLane->addShift($shift)) {
-                    engelsystem_error('Unable to add shift to new lane.');
-                }
+                $newLane->addShift($shift);
                 $lanes[$room_id][] = $newLane;
             }
         }
-
+        
         return $lanes;
     }
 
     /**
+     *
      * @return int
      */
     public function getFirstBlockStartTime()
@@ -119,6 +122,7 @@ class ShiftCalendarRenderer
     }
 
     /**
+     *
      * @return int
      */
     public function getLastBlockEndTime()
@@ -127,6 +131,7 @@ class ShiftCalendarRenderer
     }
 
     /**
+     *
      * @return float
      */
     public function getBlocksPerSlot()
@@ -148,9 +153,9 @@ class ShiftCalendarRenderer
             return '';
         }
         return div('shift-calendar', [
-                $this->renderTimeLane(),
-                $this->renderShiftLanes()
-            ]) . $this->renderLegend();
+            $this->renderTimeLane(),
+            $this->renderShiftLanes()
+        ]) . $this->renderLegend();
     }
 
     /**
@@ -166,45 +171,41 @@ class ShiftCalendarRenderer
                 $html .= $this->renderLane($lane);
             }
         }
-
+        
         return $html;
     }
 
     /**
      * Renders a single lane
      *
-     * @param ShiftCalendarLane $lane The lane to render
+     * @param ShiftCalendarLane $lane
+     *            The lane to render
      * @return string
      */
     private function renderLane(ShiftCalendarLane $lane)
     {
         global $user;
-
+        
         $shift_renderer = new ShiftCalendarShiftRenderer();
         $html = '';
         $rendered_until = $this->getFirstBlockStartTime();
-
+        
         foreach ($lane->getShifts() as $shift) {
             while ($rendered_until + ShiftCalendarRenderer::SECONDS_PER_ROW <= $shift['start']) {
                 $html .= $this->renderTick($rendered_until);
                 $rendered_until += ShiftCalendarRenderer::SECONDS_PER_ROW;
             }
-
-            list($shift_height, $shift_html) = $shift_renderer->render(
-                $shift,
-                $this->needed_angeltypes[$shift['SID']],
-                $this->shift_entries[$shift['SID']],
-                $user
-            );
+            
+            list ($shift_height, $shift_html) = $shift_renderer->render($shift, $this->needed_angeltypes[$shift['SID']], $this->shift_entries[$shift['SID']], $user);
             $html .= $shift_html;
             $rendered_until += $shift_height * ShiftCalendarRenderer::SECONDS_PER_ROW;
         }
-
+        
         while ($rendered_until < $this->getLastBlockEndTime()) {
             $html .= $this->renderTick($rendered_until);
             $rendered_until += ShiftCalendarRenderer::SECONDS_PER_ROW;
         }
-
+        
         return div('lane', [
             div('header', $lane->getHeader()),
             $html
@@ -214,21 +215,23 @@ class ShiftCalendarRenderer
     /**
      * Renders a tick/block for given time
      *
-     * @param int     $time  unix timestamp
-     * @param boolean $label Should time labels be generated?
+     * @param int $time
+     *            unix timestamp
+     * @param boolean $label
+     *            Should time labels be generated?
      * @return string rendered tick html
      */
     private function renderTick($time, $label = false)
     {
         if ($time % (24 * 60 * 60) == 23 * 60 * 60) {
-            if (!$label) {
+            if (! $label) {
                 return div('tick day');
             }
             return div('tick day', [
                 date('m-d<b\r />H:i', $time)
             ]);
         } elseif ($time % (60 * 60) == 0) {
-            if (!$label) {
+            if (! $label) {
                 return div('tick hour');
             }
             return div('tick hour', [
@@ -250,7 +253,7 @@ class ShiftCalendarRenderer
                 _('Time')
             ])
         ];
-        for ($block = 0; $block < $this->getBlocksPerSlot(); $block++) {
+        for ($block = 0; $block < $this->getBlocksPerSlot(); $block ++) {
             $thistime = $this->getFirstBlockStartTime() + ($block * ShiftCalendarRenderer::SECONDS_PER_ROW);
             $time_slot[] = $this->renderTick($thistime, true);
         }
@@ -258,7 +261,8 @@ class ShiftCalendarRenderer
     }
 
     /**
-     * @param array[] $shifts
+     *
+     * @param array[] $shifts            
      * @return int
      */
     private function calcFirstBlockStartTime($shifts)
@@ -273,7 +277,8 @@ class ShiftCalendarRenderer
     }
 
     /**
-     * @param array[] $shifts
+     *
+     * @param array[] $shifts            
      * @return int
      */
     private function calcLastBlockEndTime($shifts)
@@ -288,6 +293,7 @@ class ShiftCalendarRenderer
     }
 
     /**
+     *
      * @return int
      */
     private function calcBlocksPerSlot()
diff --git a/public/css/theme0.css b/public/css/theme0.css
index 4c09a094..050f689e 100644
--- a/public/css/theme0.css
+++ b/public/css/theme0.css
@@ -1,6 +1,6 @@
 /*!
- * Bootstrap v3.3.6 (http://getbootstrap.com)
- * Copyright 2011-2015 Twitter, Inc.
+ * Bootstrap v3.3.7 (http://getbootstrap.com)
+ * Copyright 2011-2016 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 /*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */
@@ -1095,7 +1095,6 @@ a:focus {
   text-decoration: underline;
 }
 a:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -2524,7 +2523,6 @@ select[size] {
 input[type="file"]:focus,
 input[type="radio"]:focus,
 input[type="checkbox"]:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -3015,7 +3013,6 @@ select[multiple].input-lg {
 .btn.focus,
 .btn:active.focus,
 .btn.active.focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
diff --git a/public/css/theme1.css b/public/css/theme1.css
index 3b5201b6..06ce9907 100644
--- a/public/css/theme1.css
+++ b/public/css/theme1.css
@@ -22,8 +22,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
 /*!
- * Bootstrap v3.3.6 (http://getbootstrap.com)
- * Copyright 2011-2015 Twitter, Inc.
+ * Bootstrap v3.3.7 (http://getbootstrap.com)
+ * Copyright 2011-2016 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 /*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */
@@ -1118,7 +1118,6 @@ a:focus {
   text-decoration: underline;
 }
 a:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -2547,7 +2546,6 @@ select[size] {
 input[type="file"]:focus,
 input[type="radio"]:focus,
 input[type="checkbox"]:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -3038,7 +3036,6 @@ select[multiple].input-lg {
 .btn.focus,
 .btn:active.focus,
 .btn.active.focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
diff --git a/public/css/theme2.css b/public/css/theme2.css
index 07f2ea10..9ca9babb 100644
--- a/public/css/theme2.css
+++ b/public/css/theme2.css
@@ -1,6 +1,6 @@
 /*!
- * Bootstrap v3.3.6 (http://getbootstrap.com)
- * Copyright 2011-2015 Twitter, Inc.
+ * Bootstrap v3.3.7 (http://getbootstrap.com)
+ * Copyright 2011-2016 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 /*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */
@@ -1095,7 +1095,6 @@ a:focus {
   text-decoration: underline;
 }
 a:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -2524,7 +2523,6 @@ select[size] {
 input[type="file"]:focus,
 input[type="radio"]:focus,
 input[type="checkbox"]:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -3015,7 +3013,6 @@ select[multiple].input-lg {
 .btn.focus,
 .btn:active.focus,
 .btn.active.focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
diff --git a/public/css/theme3.css b/public/css/theme3.css
index 2b5358be..abb90f23 100644
--- a/public/css/theme3.css
+++ b/public/css/theme3.css
@@ -8,8 +8,8 @@
   color: #000;
 }
 /*!
- * Bootstrap v3.3.6 (http://getbootstrap.com)
- * Copyright 2011-2015 Twitter, Inc.
+ * Bootstrap v3.3.7 (http://getbootstrap.com)
+ * Copyright 2011-2016 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 /*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */
@@ -1104,7 +1104,6 @@ a:focus {
   text-decoration: underline;
 }
 a:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -2533,7 +2532,6 @@ select[size] {
 input[type="file"]:focus,
 input[type="radio"]:focus,
 input[type="checkbox"]:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -3024,7 +3022,6 @@ select[multiple].input-lg {
 .btn.focus,
 .btn:active.focus,
 .btn.active.focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
diff --git a/public/css/theme4.css b/public/css/theme4.css
index 7f80b411..24771afd 100644
--- a/public/css/theme4.css
+++ b/public/css/theme4.css
@@ -22,8 +22,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
 /*!
- * Bootstrap v3.3.6 (http://getbootstrap.com)
- * Copyright 2011-2015 Twitter, Inc.
+ * Bootstrap v3.3.7 (http://getbootstrap.com)
+ * Copyright 2011-2016 Twitter, Inc.
  * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
  */
 /*! normalize.css v3.0.3 | MIT License | github.com/necolas/normalize.css */
@@ -1118,7 +1118,6 @@ a:focus {
   text-decoration: underline;
 }
 a:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -2547,7 +2546,6 @@ select[size] {
 input[type="file"]:focus,
 input[type="radio"]:focus,
 input[type="checkbox"]:focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
@@ -3038,7 +3036,6 @@ select[multiple].input-lg {
 .btn.focus,
 .btn:active.focus,
 .btn.active.focus {
-  outline: thin dotted;
   outline: 5px auto -webkit-focus-ring-color;
   outline-offset: -2px;
 }
diff --git a/src/Database/Db.php b/src/Database/Db.php
index 4116ffda..777b16a2 100644
--- a/src/Database/Db.php
+++ b/src/Database/Db.php
@@ -79,19 +79,36 @@ class Db
 
         return self::$stm->fetchAll(PDO::FETCH_ASSOC);
     }
+    
+    /**
+     * Run a select query and return only the first result or null if no result is found.
+     * @param string $query
+     * @param array  $bindings
+     * @return array|null
+     */
+    public static function selectOne($query, array $bindings = [])
+    {
+        $result = self::select($query, $bindings);
+        
+        if(empty($result)) {
+            return null;
+        }
+        
+        return array_shift($result);
+    }
 
     /**
      * Run an insert query
      *
      * @param string $query
      * @param array  $bindings
-     * @return int|bool
+     * @return int Row count
      */
     public static function insert($query, array $bindings = [])
     {
         self::query($query, $bindings);
 
-        return (self::$lastStatus ? self::$stm->rowCount() : false);
+        return self::$stm->rowCount();
     }
 
     /**
@@ -99,13 +116,13 @@ class Db
      *
      * @param string $query
      * @param array  $bindings
-     * @return int|bool
+     * @return int
      */
     public static function update($query, array $bindings = [])
     {
         self::query($query, $bindings);
 
-        return (self::$lastStatus ? self::$stm->rowCount() : false);
+        return self::$stm->rowCount();
     }
 
     /**
@@ -113,13 +130,13 @@ class Db
      *
      * @param string $query
      * @param array  $bindings
-     * @return int|bool
+     * @return int
      */
     public static function delete($query, array $bindings = [])
     {
         self::query($query, $bindings);
 
-        return (self::$lastStatus ? self::$stm->rowCount() : false);
+        return self::$stm->rowCount();
     }
 
     /**
diff --git a/src/Exceptions/Handler.php b/src/Exceptions/Handler.php
index 6e5b4749..c4fb639c 100644
--- a/src/Exceptions/Handler.php
+++ b/src/Exceptions/Handler.php
@@ -2,7 +2,7 @@
 
 namespace Engelsystem\Exceptions;
 
-use Exception;
+use Throwable;
 
 class Handler
 {
@@ -40,9 +40,9 @@ class Handler
     }
 
     /**
-     * @param Exception $e
+     * @param Throwable $e
      */
-    public function exceptionHandler(Exception $e)
+    public function exceptionHandler(Throwable $e)
     {
         $this->handle(
             'exception',