Refactoring database specific functionality to Database class

include/php/classes/Database.php

@@ -0,0 +1,504 @@
+<?php
+
+class Database
+{
+
+	/**
+	 * @var Database
+	 */
+	protected static $instance = null;
+
+
+	/**
+	 * @var mysqli
+	 */
+	protected $db;
+
+
+	/**
+	 * @var string
+	 */
+	protected $config;
+
+
+	/**
+	 * @var string
+	 */
+	protected $lastQuery;
+
+
+	protected function __construct($host, $user, $password, $database)
+	{
+		if(!static::isInitialized()){
+			$this->config = $database;
+
+			$this->db = new mysqli($host, $user, $password, $database);
+			if($this->db->connect_errno > 0){
+				$this->db = null;
+				die('Unable to connect to database ['.$this->db->connect_error.']');
+			}
+		}
+	}
+
+
+	protected function __clone()
+	{
+	}
+
+
+	/**
+	 * @return Database
+	 */
+	public static function getInstance()
+	{
+		return static::$instance;
+	}
+
+
+	/**
+	 * @param Database $instance
+	 */
+	protected static function setInstance($instance)
+	{
+		static::$instance = $instance;
+	}
+
+
+	/**
+	 * @param string $host
+	 * @param string $user
+	 * @param string $password
+	 * @param string $database
+	 */
+	public static function init($host, $user, $password, $database)
+	{
+		if(!static::isInitialized()){
+			static::setInstance(
+				new static($host, $user, $password, $database)
+			);
+		}
+	}
+
+
+	/**
+	 * @return bool
+	 */
+	public static function isInitialized()
+	{
+		return !is_null(static::$instance);
+	}
+
+
+	/**
+	 *
+	 */
+	public static function mustBeInitialized()
+	{
+		if(!static::isInitialized()){
+			die('Database has not been initialized.');
+		}
+	}
+
+
+	/**
+	 * Die with error and executed sql query
+	 *
+	 * @param string $errorMessage
+	 * @param string|null $sql
+	 */
+	public function dieOnDatabaseError($errorMessage, $sql = null)
+	{
+		die('There was an error running the query ['.$errorMessage.']'.(!is_null($sql) ? ' with statement "'.$sql.'"' : ''));
+	}
+
+
+	/**
+	 * Die if query not successful
+	 */
+	public function mustBeSuccessful()
+	{
+		if($this->db->errno !== 0){
+			$this->dieOnDatabaseError($this->db->error, $this->lastQuery);
+		}
+	}
+
+
+	/**
+	 * Execute query
+	 *
+	 * @param string $query
+	 *
+	 * @return bool|mysqli_result
+	 */
+	public function query($query)
+	{
+		$this->lastQuery = $query;
+
+		$result = $this->db->query($query);
+
+		$this->mustBeSuccessful();
+
+		return $result;
+	}
+
+
+	/**
+	 * @return mixed
+	 */
+	public function getInsertId()
+	{
+		return $this->db->insert_id;
+	}
+
+
+	/**
+	 * Escape string
+	 *
+	 * @param string $input
+	 *
+	 * @return string
+	 */
+	public function escape($input)
+	{
+		return $this->db->real_escape_string($input);
+	}
+
+
+	/**
+	 * @param string $table
+	 * @param array $conditions
+	 * @param string $conditionConnector
+	 * @param null $orderBy
+	 * @param int $limit
+	 *
+	 * @return bool|mysqli_result
+	 */
+	public function select($table, $conditions = array(), $conditionConnector = 'AND', $orderBy = null, $limit = 0)
+	{
+		return $this->query(
+			sprintf(
+				"SELECT * FROM `%s` %s%s%s",
+				$table,
+				static::helperWhere($conditions, $conditionConnector),
+				static::helperOrderBy($orderBy),
+				static::helperLimit($limit)
+			)
+		);
+	}
+
+
+	/**
+	 * Insert into table
+	 *
+	 * @param string $table
+	 * @param array $values
+	 *
+	 * @return mixed
+	 */
+	public function insert($table, $values)
+	{
+		if(count($values) === 0){
+			return null;
+		}
+
+		$this->query(
+			sprintf(
+				"INSERT INTO `%s` (%s) VALUES %s",
+				$table,
+				static::helperAttributeList(array_keys($values)),
+				static::helperValueList(array_values($values))
+			)
+		);
+
+		return $this->getInsertId();
+	}
+
+	/**
+	 * Update table
+	 *
+	 * @param string $table
+	 * @param array $values
+	 * @param array $conditions
+	 * @param string $conditionConnector
+	 */
+	public function update($table, $values, $conditions = array(), $conditionConnector = 'AND')
+	{
+		if(count($values) === 0){
+			return;
+		}
+
+		$sqlValues = array();
+		foreach($values as $attribute => $value){
+			$sqlValues[] = array($attribute, '=', $value);
+		}
+
+		$this->query(
+			sprintf(
+				"UPDATE `%s` SET %s %s",
+				$table,
+				static::helperConditionList($sqlValues, ','),
+				static::helperWhere($conditions, $conditionConnector)
+			)
+		);
+	}
+
+
+	/**
+	 * Count in table
+	 *
+	 * @param string $table
+	 * @param string $byAttribute
+	 * @param array $conditions
+	 * @param string $conditionConnector
+	 *
+	 * @return int
+	 */
+	public function count($table, $byAttribute, $conditions = array(), $conditionConnector = 'AND')
+	{
+		$result = $this->query(
+			sprintf(
+				"SELECT COUNT(`%s`) FROM `%s` %s",
+				$byAttribute,
+				$table,
+				static::helperWhere($conditions, $conditionConnector)
+			)
+		);
+
+		return intval($result->fetch_array(MYSQLI_NUM)[0]);
+	}
+
+
+	/**
+	 * @param string $table
+	 * @param string $attribute
+	 * @param mixed $value
+	 * @return bool
+	 */
+	public function delete($table, $attribute, $value)
+	{
+		$sql = sprintf(
+			"DELETE FROM `%s` %s",
+			$table,
+			static::helperWhere(array($attribute, $value))
+		);
+
+		$this->query($sql);
+	}
+
+
+	/**
+	 * @param string $potentialKeyword
+	 *
+	 * @return bool
+	 */
+	protected static function isKeyword($potentialKeyword)
+	{
+		return in_array(
+			strtoupper($potentialKeyword),
+			array('AS', 'ASC', 'DESC')
+		);
+	}
+
+
+	/**
+	 * @param array $attributes
+	 *
+	 * @return string
+	 */
+	public static function helperAttributeList($attributes)
+	{
+		$sqlAttributes = array();
+		foreach($attributes as $attribute){
+			if(is_string($attribute)){ // raw
+				$sqlAttributes[] = $attribute;
+				continue;
+			}
+
+			if(!is_array($attribute)){
+				$attribute = array($attribute);
+			}
+
+			$sqlPieces = array();
+			for($i = 0; $i < count($attribute); ++$i){
+				if(static::isKeyword($attribute[$i])){
+					$sqlPieces[] = sprintf("%s", $attribute[$i]);
+				}
+				elseif(isset($attribute[$i + 1]) && !static::isKeyword($attribute[$i + 1])){
+					$sqlPieces[] = sprintf("`%s`.`%s`", $attribute[$i], $attribute[++$i]);
+				}
+				else{
+					$sqlPieces[] = sprintf("`%s`", $attribute[$i]);
+				}
+			}
+
+			$sqlAttributes[] = implode(" ", $sqlPieces);
+		}
+
+		return sprintf(
+			"%s",
+			implode(', ', $sqlAttributes)
+		);
+	}
+
+
+	/**
+	 * @param mixed $value
+	 *
+	 * @return string
+	 */
+	public static function helperValue($value)
+	{
+		if(is_null($value) || (is_string($value) && strtoupper($value) === 'NULL')){
+			return "NULL";
+		}
+		elseif(is_array($value)){
+			return static::helperValueList($value);
+		}
+
+		return sprintf(
+			"'%s'",
+			static::getInstance()->escape($value)
+		);
+	}
+
+	/**
+	 * @param array $values
+	 *
+	 * @return string
+	 */
+	public static function helperValueList($values)
+	{
+		$sqlValues = array();
+
+		foreach($values as $val){
+			$sqlValues[] = static::helperValue($val);
+		}
+
+		return sprintf(
+			"(%s)",
+			implode(', ', $sqlValues)
+		);
+	}
+
+	/**
+	 * @param array $conditions
+	 *     array('attr', '=', '3') => "`attr` = '3'"
+	 *     array(
+	 *         array('`attr` = '3') (raw SQL) => `attr` = '3'
+	 *         array('attr', 3) => `attr` = '3'
+	 *         array('attr', '=', '3') => `attr` = '3'
+	 *         array('attr', '<=', 3) => `attr` <= '3'
+	 *         array('attr', 'LIKE', '%asd') => `attr` LIKE '%asd'
+	 *         array('attr', 'IS', null) => `attr` IS NULL
+	 *         array('attr', 'IS NOT', null) => `attr` IS NOT NULL
+	 *     )
+	 * @param string $conditionConnector AND, OR
+	 *
+	 * @return string
+	 */
+	public static function helperConditionList($conditions, $conditionConnector = 'AND')
+	{
+		// detect non nested array
+		if(count($conditions) > 0 && !is_array($conditions[0])){
+			$conditions = array($conditions);
+		}
+
+		$conditionConnector = strtoupper($conditionConnector);
+		if(in_array($conditionConnector, array('AND', 'OR'))){
+			$conditionConnector = " ".$conditionConnector;
+		}
+
+		$values = array();
+		foreach($conditions as $val){
+			switch(count($val)){
+				case 1:
+					// raw
+					$values[] = $val;
+					break;
+				case 2:
+					$v = static::helperValue($val[1]);
+					$values[] = sprintf("`%s` = %s", $val[0], $v);
+					break;
+				case 3:
+					$v = static::helperValue($val[2]);
+					$values[] = sprintf("`%s` %s %s", $val[0], strtoupper($val[1]), $v);
+					break;
+			}
+		}
+
+		return implode($conditionConnector." ", $values);
+	}
+
+	/**
+	 * @param array $conditions
+	 * @param string $conditionConnector AND, OR
+	 *
+	 * @return string
+	 */
+	public static function helperWhere($conditions, $conditionConnector = 'AND')
+	{
+		if(count($conditions) > 0){
+			return sprintf(
+				" WHERE %s",
+				static::helperConditionList($conditions, $conditionConnector)
+			);
+		}
+
+		return "";
+	}
+
+	/**
+	 * @param array|null $orderBy Examples below:
+	 *        null => ""
+	 *        array() => ""
+	 *        array('attr1' => 'asc', 'attr2' => 'desc') => " ORDER BY `attr1` ASC, `attr2` DESC"
+	 *        array('attr1') => " ORDER BY `attr1` ASC"
+	 *
+	 * @return string
+	 */
+	public static function helperOrderBy($orderBy = null)
+	{
+		if(is_null($orderBy) || count($orderBy) === 0){
+			return "";
+		}
+
+		$values = array();
+		foreach($orderBy as $key => $val){
+			if(is_int($key)){
+				$values[] = array($val);
+			}
+			else{
+				$values[] = array($key, strtoupper($val));
+			}
+		}
+
+		return sprintf(
+			" ORDER BY %s",
+			static::helperAttributeList($values)
+		);
+	}
+
+	/**
+	 * @param int|array $limit
+	 *        0 => ""
+	 *        3 => " LIMIT 3"
+	 *        array(3, 4) => " LIMIT 3,4"
+	 *
+	 * @return string
+	 */
+	public static function helperLimit($limit = 0)
+	{
+		if(is_array($limit) && count($limit) == 2){
+			$limit = $limit[0].",".$limit[1];
+		}
+
+		if(is_string($limit) || (is_int($limit) && $limit > 0)){
+			return sprintf(
+				" LIMIT %s",
+				$limit
+			);
+		}
+
+		return "";
+	}
+}

include/php/default.inc.php

@@ -40,10 +40,7 @@ else{
 /**
  * Establish database connection
  */
-$db = new mysqli(MYSQL_HOST, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE);
-if($db->connect_errno > 0){
-	die('Unable to connect to database [' . $db->connect_error . ']');
-}
+Database::init(MYSQL_HOST, MYSQL_USER, MYSQL_PASSWORD, MYSQL_DATABASE);
 
 
 /**

include/php/global.inc.php

@@ -1,14 +1,5 @@
 <?php
 
-/**
- * @param string $errorMessage
- * @param null|string $sql
- */
-function dbError($errorMessage, $sql = null)
-{
-	die('There was an error running the query ['.$errorMessage.']'.(!is_null($sql)?' with statement "'.$sql.'"':''));
-}
-
 
 /**
  * Add message to logfile

include/php/models/AbstractModel.php

@@ -202,7 +202,7 @@ abstract class AbstractModel
 	{
 		$rows = array();
 
-		while($row = $result->fetch_assoc()) {
+		while($row = $result->fetch_assoc()){
 			$rows[] = $row;
 		}
 
@@ -258,229 +258,6 @@ abstract class AbstractModel
 	}
 
 
-	/**
-	 * @param array $attributes
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperAttributeList($attributes)
-	{
-		$sql = "%s";
-		$values = array();
-
-		$keywords = array('AS', 'ASC', 'DESC');
-
-		foreach($attributes as $val){
-			if(!is_array($val)){
-				// raw
-				$values[] = $val;
-				continue;
-			}
-
-			switch(count($val)){
-				case 1:
-					$values[] = "`{$val[0]}`";
-					break;
-				case 2:
-					if(in_array(strtoupper($val[1]), $keywords)){
-						$values[] = "`{$val[0]}` {$val[1]}";
-					}
-					else{
-						$values[] = "`{$val[0]}`.`{$val[1]}`";
-					}
-					break;
-				case 3:
-					if(in_array(strtoupper($val[1]), $keywords)){
-						$values[] = "`{$val[0]}` {$val[1]} `{$val[2]}`";
-					}
-					elseif(in_array(strtoupper($val[2]), $keywords)){
-						$values[] = "`{$val[0]}`.`{$val[1]}` {$val[2]}";
-					}
-					break;
-				case 4:
-					if(in_array(strtoupper($val[1]), $keywords)){
-						$values[] = "`{$val[0]}` {$val[1]} `{$val[2]}`.`{$val[3]}`";
-					}
-					elseif(in_array(strtoupper($val[2]), $keywords)){
-						$values[] = "`{$val[0]}`.`{$val[1]}` {$val[2]} `{$val[3]}`";
-					}
-					else{
-						$values[] = "`{$val[0]}`.`{$val[1]}` `{$val[2]}`.`{$val[3]}`";
-					}
-					break;
-				case 5:
-					if(in_array(strtoupper($val[2]), $keywords)){
-						$values[] = "`{$val[0]}`.`{$val[1]}` {$val[2]} `{$val[3]}`.`{$val[4]}`";
-					}
-					break;
-			}
-		}
-
-		return sprintf($sql, implode(', ', $values));
-	}
-
-
-	/**
-	 * @param mixed $value
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperValue($value)
-	{
-		global $db;
-		if(is_null($value) || (is_string($value) && strtoupper($value) === 'NULL')){
-			return "NULL";
-		}
-		elseif(is_array($value)){
-			return static::sqlHelperValueList($value);
-		}
-
-		return "'{$db->escape_string($value)}'";
-	}
-
-
-	/**
-	 * @param array $values
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperValueList($values)
-	{
-		$sql = "(%s)";
-		$sqlValues = array();
-
-		foreach($values as $val){
-			$sqlValues[] = static::sqlHelperValue($val);
-		}
-
-		return sprintf($sql, implode(', ', $sqlValues));
-	}
-
-
-	/**
-	 * @param array $conditions
-	 *     array('attr', '=', '3') => "`attr` = '3'"
-	 *     array(
-	 *         array('`attr` = '3') (raw SQL) => `attr` = '3'
-	 *         array('attr', 3) => `attr` = '3'
-	 *         array('attr', '=', '3') => `attr` = '3'
-	 *         array('attr', '<=', 3) => `attr` <= '3'
-	 *         array('attr', 'LIKE', '%asd') => `attr` LIKE '%asd'
-	 *         array('attr', 'IS', null) => `attr` IS NULL
-	 *         array('attr', 'IS NOT', null) => `attr` IS NOT NULL
-	 *     )
-	 * @param string $conditionConnector AND, OR
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperConditionList($conditions, $conditionConnector = 'AND')
-	{
-		$values = array();
-
-		// detect non nested array
-		if(count($conditions) > 0 && !is_array($conditions[0])){
-			$conditions = array($conditions);
-		}
-
-		$conditionConnector = strtoupper($conditionConnector);
-		if(in_array($conditionConnector, array('AND', 'OR'))){
-			$conditionConnector = " ".$conditionConnector;
-		}
-
-		$sql = "`%s` %s %s";
-
-		foreach($conditions as $val){
-			switch(count($val)){
-				case 1:
-					// raw
-					$values[] = $val;
-					break;
-				case 2:
-					$v = static::sqlHelperValue($val[1]);
-					$values[] = sprintf($sql, $val[0], "=", $v);
-					break;
-				case 3:
-					$v = static::sqlHelperValue($val[2]);
-					$values[] = sprintf($sql, $val[0], strtoupper($val[1]), $v);
-					break;
-			}
-		}
-
-		return implode($conditionConnector." ", $values);
-	}
-
-
-	/**
-	 * @param array $conditions
-	 * @param string $conditionConnector AND, OR
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperWhere($conditions, $conditionConnector = 'AND')
-	{
-		if(count($conditions) > 0){
-			$sql = " WHERE %s";
-
-			return sprintf($sql, static::sqlHelperConditionList($conditions, $conditionConnector));
-		}
-
-		return "";
-	}
-
-	/**
-	 * @param array|null $orderBy Examples below:
-	 *        null => ""
-	 *        array() => ""
-	 *        array('attr1' => 'asc', 'attr2' => 'desc') => " ORDER BY `attr1` ASC, `attr2` DESC "
-	 *        array('attr1') => " ORDER BY `attr1` ASC "
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperOrderBy($orderBy = null)
-	{
-		if(!is_null($orderBy) && count($orderBy) > 0){
-			$sql = " ORDER BY %s";
-
-			$values = array();
-			foreach($orderBy as $key => $val){
-				if(is_int($key)){
-					$values[] = array($val);
-				}
-				else{
-					$values[] = array($key, strtoupper($val));
-				}
-			}
-
-			return sprintf($sql, static::sqlHelperAttributeList($values));
-		}
-
-		return "";
-	}
-
-
-	/**
-	 * @param int|array $limit
-	 *        0 => ""
-	 *        3 => " LIMIT 3 "
-	 *        array(3, 4) => " LIMIT 3,4 "
-	 *
-	 * @return string
-	 */
-	protected static function sqlHelperLimit($limit = 0)
-	{
-		$sql = " LIMIT %s";
-
-		if(is_string($limit) || (is_int($limit) && $limit > 0)){
-			return sprintf($sql, $limit);
-		}
-		elseif(is_array($limit) && count($limit) == 2){
-			return sprintf($sql, $limit[0].",".$limit[1]);
-		}
-
-		return "";
-	}
-
-
 	/**
 	 * Find all models by raw sql
 	 *
@@ -491,11 +268,7 @@ abstract class AbstractModel
 	 */
 	public static function findAllRaw($sql, $useSpecificModel = null)
 	{
-		global $db;
-
-		if(!$result = $db->query($sql)){
-			dbError($db->error, $sql);
-		}
+		$result = Database::getInstance()->query($sql);
 
 		if(is_null($useSpecificModel)){
 			return static::createMultipleFromDbResult($result);
@@ -518,11 +291,7 @@ abstract class AbstractModel
 	 */
 	public static function findRaw($sql, $useSpecificModel = null)
 	{
-		global $db;
-
-		if(!$result = $db->query($sql)){
-			dbError($db->error, $sql);
-		}
+		$result = Database::getInstance()->query($sql);
 
 		if(is_null($useSpecificModel)){
 			return static::createFromDbResult($result);
@@ -538,49 +307,43 @@ abstract class AbstractModel
 	/**
 	 * Find all models
 	 *
-	 * @param array|null $orderBy see sqlHelperOrderBy
+	 * @param array|null $orderBy see helperOrderBy
 	 *
 	 * @return ModelCollection|static[]
 	 */
 	public static function findAll($orderBy = null)
 	{
-		$sql = "SELECT * FROM `".static::$table."`"
-			.static::sqlHelperOrderBy($orderBy);
-
-		return static::findAllRaw($sql);
+		return static::findWhere(array(), 'AND', $orderBy);
 	}
 
 
 	/**
 	 * Find models by a condition
 	 *
-	 * @param array $conditions see sqlHelperConditionArray
-	 * @param string $conditionConnector see sqlHelperConditionArray
+	 * @param array $conditions see helperConditionArray
+	 * @param string $conditionConnector see helperConditionArray
 	 * @param array|null $orderBy
-	 * @param int $limit see sqlHelperLimit
+	 * @param int $limit see helperLimit
 	 *
 	 * @return ModelCollection|static[]|AbstractModel|null
 	 */
 	public static function findWhere($conditions = array(), $conditionConnector = 'AND', $orderBy = null, $limit = 0)
 	{
-		$sql = "SELECT * FROM `".static::$table."`"
-			.static::sqlHelperWhere($conditions, $conditionConnector)
-			.static::sqlHelperOrderBy($orderBy)
-			.static::sqlHelperLimit($limit);
+		$result = Database::getInstance()->select(static::$table, $conditions, $conditionConnector, $orderBy, $limit);
 
 		if($limit === 1){
-			return static::findRaw($sql);
+			return static::createFromDbResult($result);
 		}
 
-		return static::findAllRaw($sql);
+		return static::createMultipleFromDbResult($result);
 	}
 
 
 	/**
 	 * Find first model matching a condition
 	 *
-	 * @param array $conditions see sqlHelperConditionArray
-	 * @param string $conditionConnector see sqlHelperConditionArray
+	 * @param array $conditions see helperConditionArray
+	 * @param string $conditionConnector see helperConditionArray
 	 * @param array|null $orderBy
 	 *
 	 * @return AbstractModel|null
@@ -606,66 +369,28 @@ abstract class AbstractModel
 
 	/**
 	 * Save model data to database
-	 *
-	 * @return bool
 	 */
 	public function save()
 	{
-		global $db;
-
 		$data = $this->preSave($this->data);
 
-		if(is_null($this->getId())){
-			// insert
-
-			$attributes = array();
-			$values = array();
-
-			foreach($this->attributeDbAttributeMapping as $attribute => $sqlAttribute){
-				if($sqlAttribute === static::$idAttribute){
-					continue;
-				}
-
-				$attributes[] = array($sqlAttribute);
-				$values[] = $data[$attribute];
+		$values = array();
+		foreach($this->attributeDbAttributeMapping as $attribute => $sqlAttribute){
+			if($sqlAttribute === static::$idAttribute){
+				continue;
 			}
 
-			$sql = "INSERT INTO `".static::$table."`"
-				." (".static::sqlHelperAttributeList($attributes).")"
-				." VALUES ".static::sqlHelperValueList($values);
+			$values[$sqlAttribute] = $data[$attribute];
 		}
-		else{
-			// update
 
-			$values = array();
-			foreach($this->attributeDbAttributeMapping as $attribute => $sqlAttribute){
-				if($sqlAttribute === static::$idAttribute){
-					continue;
-				}
-
-				$values[] = array($sqlAttribute, '=', $data[$attribute]);
-			}
+		if(is_null($this->getId())){
+			$insertId = Database::getInstance()->insert(static::$table, $values);
 
-			$sql = "UPDATE `".static::$table."`"
-				." SET ".static::sqlHelperConditionList($values, ',')
-				.static::sqlHelperWhere(array(static::$idAttribute, $this->getId()));
+			$this->setId(intval($insertId));
 		}
-
-
-		if($stmt = $db->prepare($sql)){
-			if($stmt->execute()){
-				if(is_null($this->getId())){
-					$this->setId(intval($db->insert_id));
-				}
-
-				return true;
-			}
-			else{
-				dbError($db->error, $sql);
-			}
+		else{
+			Database::getInstance()->update(static::$table, $values, array(static::$idAttribute, $this->getId()));
 		}
-
-		return false;
 	}
 
 	/**
@@ -675,23 +400,39 @@ abstract class AbstractModel
 	 */
 	public function delete()
 	{
-		global $db;
-
 		if(!is_null($this->getId())){
-			$sql = "DELETE FROM `".static::$table."`"
-				.static::sqlHelperWhere(array(static::$idAttribute, $this->getId()));
 
-			if($stmt = $db->prepare($sql)){
-				if($stmt->execute()){
-					return true;
-				}
-				else{
-					dbError($db->error, $sql);
-				}
-			}
+			Database::getInstance()->delete(static::$table, static::$idAttribute, $this->getId());
+
+			return true;
 		}
 
 		return false;
 	}
 
+
+	/**
+	 * Count models by a condition
+	 *
+	 * @param array $conditions see helperConditionArray
+	 * @param string $conditionConnector see helperConditionArray
+	 *
+	 * @return int
+	 */
+	public static function countWhere($conditions = array(), $conditionConnector = 'AND')
+	{
+		return Database::getInstance()->count(static::$table, static::$idAttribute, $conditions, $conditionConnector);
+	}
+
+
+	/**
+	 * Count all models
+	 *
+	 * @return int
+	 */
+	public static function count()
+	{
+		return static::countWhere();
+	}
+
 }

include/php/models/AbstractRedirect.php

@@ -194,7 +194,7 @@ abstract class AbstractRedirect extends AbstractModel
 		$domains = array();
 		foreach($sources as $source){
 			$emailParts = explode('@', $source);
-			if(count($emailParts) === 2) {
+			if(count($emailParts) === 2){
 				$domains[] = $emailParts[1];
 			}
 		}
@@ -296,7 +296,7 @@ UNION
 	public static function findMultiAll($orderBy = array(DBC_ALIASES_SOURCE))
 	{
 		$sql = static::generateRedirectBaseQuery()
-			.static::sqlHelperOrderBy($orderBy);
+			.Database::helperOrderBy($orderBy);
 
 		return static::findAllRaw($sql);
 	}
@@ -305,9 +305,9 @@ UNION
 	public static function findMultiWhere($conditions = array(), $conditionConnector = 'AND', $orderBy = null, $limit = 0)
 	{
 		$sql = static::generateRedirectBaseQuery()
-			.static::sqlHelperWhere($conditions, $conditionConnector)
-			.static::sqlHelperOrderBy($orderBy)
-			.static::sqlHelperLimit($limit);
+			.Database::helperWhere($conditions, $conditionConnector)
+			.Database::helperOrderBy($orderBy)
+			.Database::helperLimit($limit);
 
 		if($limit === 1){
 			return static::findRaw($sql);

include/php/models/Domain.php

@@ -65,13 +65,7 @@ class Domain extends AbstractModel
 	 */
 	public function countUsers()
 	{
-		global $db;
-
-		if(!$result = $db->query("SELECT COUNT(`".DBC_USERS_ID."`) FROM `".DBT_USERS."` WHERE `".DBC_USERS_DOMAIN."` = '{$this->getDomain()}'")){
-			dbError($db->error);
-		}
-
-		return $result->fetch_array(MYSQLI_NUM)[0];
+		return User::countWhere(array(DBC_USERS_DOMAIN, $this->getDomain()));
 	}
 
 
@@ -80,13 +74,7 @@ class Domain extends AbstractModel
 	 */
 	public function countRedirects()
 	{
-		global $db;
-
-		if(!$result = $db->query("SELECT COUNT(`".DBC_ALIASES_ID."`) FROM `".DBT_ALIASES."` WHERE `".DBC_ALIASES_SOURCE."` LIKE '%@{$this->getDomain()}%'")){
-			dbError($db->error);
-		}
-
-		return $result->fetch_array(MYSQLI_NUM)[0];
+		return AbstractRedirect::countWhere(array(DBC_ALIASES_SOURCE, 'LIKE', "%@{$this->getDomain()}%"));
 	}
 
 }

include/php/models/User.php

@@ -157,14 +157,11 @@ class User extends AbstractModel
 	 */
 	public static function getMailboxLimitDefault()
 	{
-		global $db;
-
 		if(defined('DBC_USERS_MAILBOXLIMIT')){
 
 			$sql = "SELECT DEFAULT(".DBC_USERS_MAILBOXLIMIT.") FROM `".static::$table."` LIMIT 1";
-			if(!$result = $db->query($sql)){
-				dbError($db->error, $sql);
-			}
+
+			$result = Database::getInstance()->query($sql);
 
 			if($result->num_rows === 1){
 				$row = $result->fetch_array();
@@ -227,7 +224,7 @@ class User extends AbstractModel
 		global $adminDomainLimits;
 
 		if($this->isDomainLimited()){
-			if (!is_array($adminDomainLimits[$this->getEmail()])) {
+			if(!is_array($adminDomainLimits[$this->getEmail()])){
 				throw new InvalidArgumentException('Config value of admin domain limits for email "'.$this->getEmail().'" needs to be of type array.');
 			}