public function and_where($arg = null, $val = null, $sign = '=')
    {
        return self::where($arg, $val, $sign, 'AND');
    }
public function and_where($arg = null, $val = null, $sign = '=')
    {
        return self::where($arg, $val, $sign, 'AND');
    }
public function and_where ( $ arg = null , $ val = null , $ sign = '=' ) { return self :: where ( $ arg , $ val , $ sign , 'AND' ) ; }
Alias for a AND WHERE statement

@param string $arg The argument of the WHERE statement
@param string $val The value of the argument
@param string $sign The sign used to build the WHERE statement (default is '=')
@return object The whole object itself for method chaining
@see self::where()
Alias for a AND WHERE statement