DB Class like WordPress DB

db.php

<?php

class db{
	protected $con = false;

	public function __destruct(){
		return null;
	}
	
	public function connect($dbhost, $dbname, $dbuser, $dbpass){
		try{
			$this->con = new PDO(sprintf('mysql:host=%s;dbname=%s;charset=utf8', $dbhost, $dbname), $dbuser, $dbpass);	
			$this->con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		} catch (PDOException $e) {
			//echo 'Falló la conexión: ' . $e->getMessage();
			return false;
		}

        return $this->con;
    }

	public function close(){
		$this->con = false;
	}

	public function count($tablename, $conditions = NULL, $values = NULL){
		if( empty($tablename) || !is_string($tablename) )
			return false;

		$sql = sprintf('SELECT COUNT(*) AS count FROM `%s`', $tablename);

		$conditions = trim($conditions);

		if( !is_null($conditions) ){
			$tokens     = explode(' ', $conditions);

			$method = array('ORDER', 'LIMIT', 'JOIN', 'LEFT', 'INNER', 'RIGHT', 'OUTER');

			if( in_array($tokens[0], $method) ){
				$sql .= ' '.str_replace('?', '%s', $conditions);	
			} else {
				$sql .= ' WHERE '.str_replace('?', '%s', $conditions);
			}

			if( !is_null($values) ){
				if( is_array($values) ){
					$sql = $this->prepare($sql, $values);	
				} else {
					$args = func_get_args();
					array_shift($args);
					array_shift($args);

					$sql = $this->prepare($sql, $args);
				}
			}
		}

		$res = $this->get_results( $sql );
		
		if( $res == FALSE ) return false;

		return $res[0]->count;
	}

	public function dispense($tablename, $id=NULL){
		if( empty($tablename) || !is_string($tablename) )
			return false;

		$new = new db();
		$new->get_primary_key($tablename);
	
		if( !is_null($id) ){
			$res = $new->get_results( sprintf('SELECT * FROM `%s` WHERE `%s`="%s" LIMIT 1', $tablename, $new->primary_key, $id) );

			if( $res == FALSE )
				return false;

			foreach($new->cols as $col){
				$new->$col = $res[0]->$col;
			}
		}
		return $new;
	}

	public function find($tablename, $conditions = NULL, $values = NULL){
		if( empty($tablename) || !is_string($tablename) )
			return false;

		$sql = sprintf('SELECT * FROM `%s`', $tablename);

		if( !is_null($conditions) ){
			$conditions = trim($conditions);
			$tokens     = explode(' ', $conditions);

			$method = array('ORDER', 'LIMIT', 'JOIN', 'LEFT', 'INNER', 'RIGHT', 'OUTER');

			if( in_array($tokens[0], $method) ){
				$sql .= ' '.str_replace('?', '%s', $conditions);	
			} else {
				$sql .= ' WHERE '.str_replace('?', '%s', $conditions);
			}

			if( !is_null($values) ){
				if( is_array($values) ){
					$sql = $this->prepare($sql, $values);
				} else {
					$args = func_get_args();
					array_shift($args);
					array_shift($args);
					
					$sql = $this->prepare($sql, $args);
				}
			}
		}
		
		$res = $this->get_results( $sql );
		
		if( $res == FALSE ) return false;

		return $res;
	}

	public function query($query){
		if(!$this->con){
			if( $this->connect() == FALSE )
				return false;
		}

		$query = apply_filters( 'query', $query );

		try{
			$this->res = $this->con->query($query);

			
			if ( preg_match( '/^\s*(select)\s/i', $query ) ) {
				$this->cols = array();

				for($i = 0; $i < $this->res->columnCount(); ++$i){
					$col = $this->res->getColumnMeta($i);
					$this->cols[] = $col['name'];

					if( in_array('primary_key', $col['flags']) ){
						$this->primary_key = $col['name'];
					}
				}
			} elseif ( preg_match( '/^\s*(insert|replace)\s/i', $query ) ) {
				$this->last_insert = $this->con->lastInsertId();

				if( isset($this->primary_key) && isset($this->table_name) ){
					$primary = $this->primary_key;
					$this->$primary = $this->last_insert;
				}
				return $this->last_insert;
			}
			return $this->res->rowCount();
		} catch( PDOException $e ){
			return false;
		}
	}

	public function last_id(){
		return $this->con->lastInsertId();
	}
	
	public function num_rows(){
		return $this->res->rowCount();
	}

	public function get_column_names($table){
		if(!$this->con)
			$this->connect();

		$rs = $this->con->query(sprintf('SELECT * FROM %s LIMIT 0', $table));
		for ($i = 0; $i < $rs->columnCount(); $i++) {
			$col = $rs->getColumnMeta($i);
			$columns[] = $col['name'];
		}
		return $rs;
	}

	public function get_var($query = null){
		$res = $this->get_results($query);

		if( !$res )
			return false;

		$first = (array)reset($res);
		return reset($first);
	}

	public function get_result($query = null){
		return $this->get_results($query);
	}

	public function get_results($query = null){
		if(!is_null($query)){
			if( !$this->query($query) )
				return false;
		}

		$result = array();

		while( $res = $this->res->fetchObject() ){
			$result[] = $res;
		}

		return $result;
	}

	public function get_primary_key($tablename){
		if( empty($tablename) || !is_string($tablename) )
			return false;

		$this->table_name = $tablename;
		$this->query(sprintf('SELECT * FROM %s LIMIT 0', $tablename));

		return $this->primary_key;
	}

	public function insert($table, $data){
		$fields           = array_keys($data);
		$formatted_fields = array();
		foreach($fields as $field){
			$formatted_fields[] = '%s';
		}
		$sql = 'INSERT INTO `'.$table.'` (`'.implode('`,`', $fields).'`) VALUES ('. implode(',', $formatted_fields).')'; 
	    
	    return $this->query($this->prepare($sql, $data));
	}

	public function last_query(){
		if( !isset($this->res) || $this->res == FALSE )
			return false;

		return $this->res->queryString;
	}

	public function remove(){
		if( !isset($this->primary_key) || !isset($this->table_name) )
			return false;

		
		$primary = $this->primary_key;

		if( isset($this->$primary) || !empty($this->$primary) || !is_null($this->$primary) ){
			return $this->delete($this->table_name, array($primary => $this->$primary));
		}

		return false;
	}

	public function save(){
		$primary = $this->primary_key;

		$data = array();
		foreach($this->cols as $col){
			if( isset($this->$col) )
				$data[$col] = $this->$col;
		}

		if( isset($this->$primary) ){
			return $this->update($this->table_name, $data, array($primary => $this->$primary));
		} else {
			return $this->insert($this->table_name, $data);
		}
	}

	public function update($table, $data, $where){
		$bits = $wheres = array();
		foreach($data as $key => $value){
			$form = '%s';
			$bits[] = "`$key` = {$form}";
		}
		foreach($where as $key => $value){
			$form = '%s';
			$wheres[] = "`$key` = {$form}";
		}

		$sql = sprintf('UPDATE `%s` SET %s WHERE %s', $table, implode(', ', $bits), implode(' AND ', $wheres));
		
		return $this->query( $this->prepare($sql, array_merge(array_values($data), array_values($where))) );
	}

	public function delete($table, $where, $where_format = null){
		if(!is_array($where))
			return false;

		$where = $this->process_fields( $table, $where, $where_format );
		if ( false === $where ) {
			return false;
		}

		$conditions = $values = array();
		foreach($where as $field => $value){
			if ( is_null( $value['value'] ) ) {
				$conditions[] = "`$field` IS NULL";
				continue;
			}

			$conditions[] = "`$field` = " . $value['format'];
			$values[] = $value['value'];
		}

		$conditions = implode( ' AND ', $conditions );

		$sql = "DELETE FROM `$table` WHERE $conditions";

		return $this->query($this->prepare($sql, $values));
	}

	public function prepare($query, $args){
		if(is_null($query))
			return;

		$args = func_get_args();
		array_shift( $args );

		if ( isset( $args[0] ) && is_array($args[0]) )
			$args = $args[0];

		$query = str_replace( "'%s'", '%s', $query );
		$query = str_replace( '"%s"', '%s', $query );
		$query = preg_replace( '|(?<!%)%f|' , '%F', $query );
		$query = preg_replace( '|(?<!%)%s|', "'%s'", $query );
		array_walk( $args, array($this, 'escape_by_ref') );
		return @vsprintf($query, $args);
	}

	public function escape_by_ref(&$string){
		if( !is_float($string) )
			$string = $this->_real_escape( $string );
	}

	private function _real_escape($string){
		if($this->con)
			return substr($this->con->quote($string), 1, -1);
		
		return addslashes($string);
	}

	protected function process_fields( $table, $data, $format ) {
		$data = $this->process_field_formats( $data, $format );
		if ( false === $data ) {
			return false;
		}

		return $data;
	}

	protected function process_field_formats( $data, $format ) {
		$formats = $original_formats = (array) $format;

		foreach ( $data as $field => $value ) {
			$value = array(
				'value'  => $value,
				'format' => '%s',
			);

			if ( ! empty( $format ) ) {
				$value['format'] = array_shift( $formats );
				if ( ! $value['format'] ) {
					$value['format'] = reset( $original_formats );
				}
			} elseif ( isset( $this->field_types[ $field ] ) ) {
				$value['format'] = $this->field_types[ $field ];
			}

			$data[ $field ] = $value;
		}

		return $data;
	}

}