1 files changed, 25 insertions, 18 deletions
diff --git a/includes/mysqli_provider.php b/includes/mysqli_provider.php
index 9f901a40..9f4f1396 100644
--- a/includes/mysqli_provider.php
+++ b/includes/mysqli_provider.php
@@ -5,16 +5,23 @@
  */
 function sql_close() {
   global $sql_connection;
-
+  
   return $sql_connection->close();
 }
 
 /**
+ * Return NULL if given value is null.
+ */
+function sql_null($value = null) {
+  return $value == null ? 'NULL' : ("'" . sql_escape($value) . "'");
+}
+
+/**
  * Start new transaction.
  */
 function sql_transaction_start() {
   global $sql_nested_transaction_level;
-
+  
   if ($sql_nested_transaction_level ++ == 0)
     return sql_query("BEGIN");
   else
@@ -26,7 +33,7 @@ function sql_transaction_start() {
  */
 function sql_transaction_commit() {
   global $sql_nested_transaction_level;
-
+  
   if (-- $sql_nested_transaction_level == 0)
     return sql_query("COMMIT");
   else
@@ -38,7 +45,7 @@ function sql_transaction_commit() {
  */
 function sql_transaction_rollback() {
   global $sql_nested_transaction_level;
-
+  
   if (-- $sql_nested_transaction_level == 0)
     return sql_query("ROLLBACK");
   else
@@ -48,17 +55,17 @@ function sql_transaction_rollback() {
 /**
  * Logs an sql error.
  *
- * @param string $message
+ * @param string $message          
  * @return false
  */
 function sql_error($message) {
   sql_close();
-
+  
   $message = trim($message) . "\n";
   $message .= debug_string_backtrace() . "\n";
-
+  
   error_log('mysql_provider error: ' . $message);
-
+  
   return false;
 }
 
@@ -77,19 +84,19 @@ function sql_error($message) {
  */
 function sql_connect($host, $user, $pass, $db) {
   global $sql_connection;
-
+  
   $sql_connection = new mysqli($host, $user, $pass, $db);
   if ($sql_connection->connect_errno)
     return sql_error("Unable to connect to MySQL: " . $sql_connection->connect_error);
-
+  
   $result = $sql_connection->query("SET CHARACTER SET utf8;");
   if (! $result)
     return sql_error("Unable to set utf8 character set (" . $sql_connection->errno . ") " . $sql_connection->error);
-
+  
   $result = $sql_connection->set_charset('utf8');
   if (! $result)
     return sql_error("Unable to set utf8 names (" . $sql_connection->errno . ") " . $sql_connection->error);
-
+  
   return $sql_connection;
 }
 
@@ -110,12 +117,12 @@ function sql_select_db($db_name) {
 /**
  * MySQL SELECT query
  *
- * @param string $query
+ * @param string $query          
  * @return Result array or false on error
  */
 function sql_select($query) {
   global $sql_connection;
-
+  
   $result = $sql_connection->query($query);
   if ($result) {
     $data = array();
@@ -129,12 +136,12 @@ function sql_select($query) {
 /**
  * MySQL execute a query
  *
- * @param string $query
+ * @param string $query          
  * @return mysqli_result boolean resource or false on error
  */
 function sql_query($query) {
   global $sql_connection;
-
+  
   $result = $sql_connection->query($query);
   if ($result) {
     return $result;
@@ -155,7 +162,7 @@ function sql_id() {
 /**
  * Escape a string for a sql query.
  *
- * @param string $query
+ * @param string $query          
  * @return string
  */
 function sql_escape($query) {
@@ -166,7 +173,7 @@ function sql_escape($query) {
 /**
  * Count query result lines.
  *
- * @param string $query
+ * @param string $query          
  * @return int Count of result lines
  */
 function sql_num_query($query) {