public function whereNull($field, $condition = 'NULL', $operator = 'AND')
    {
        if ( ! in_array($condition, ['NULL', 'NOT NULL']) || ! in_array($operator, ['AND', 'OR'])) {
            throw new \InvalidArgumentException("Logical operator");
        }
        // is the first time call where method ?
        if ($this->_where_str == '') {
            $this->_where_str = ' WHERE ';
        } else {
            $this->_where_str .= ' '.$operator.' ';
        }

        $this->_where_str .= self::_wrapRow($field).' IS '.$condition.' ';

        return $this;
    }
public function whereNull($field, $condition = 'NULL', $operator = 'AND')
    {
        if ( ! in_array($condition, ['NULL', 'NOT NULL']) || ! in_array($operator, ['AND', 'OR'])) {
            throw new \InvalidArgumentException("Logical operator");
        }
        // is the first time call where method ?
        if ($this->_where_str == '') {
            $this->_where_str = ' WHERE ';
        } else {
            $this->_where_str .= ' '.$operator.' ';
        }

        $this->_where_str .= self::_wrapRow($field).' IS '.$condition.' ';

        return $this;
    }
public function whereNull ( $ field , $ condition = 'NULL' , $ operator = 'AND' ) { if ( ! in_array ( $ condition , [ 'NULL' , 'NOT NULL' ] ) || ! in_array ( $ operator , [ 'AND' , 'OR' ] ) ) { throw new \ InvalidArgumentException ( "Logical operator" ) ; } // is the first time call where method ? if ( $ this -> _where_str == '' ) { $ this -> _where_str = ' WHERE ' ; } else { $ this -> _where_str .= ' ' . $ operator . ' ' ; } $ this -> _where_str .= self :: _wrapRow ( $ field ) . ' IS ' . $ condition . ' ' ; return $ this ; }
build whereNull string

@param  string $field
@param  string $condition
@param  string $operator
@return  self
@throws  \InvalidArgumentException
build whereNull string