public function isNotNull($field)
    {
        if (!($field instanceof ExpressionInterface)) {
            $field = new IdentifierExpression($field);
        }

        return $this->add(new UnaryExpression('IS NOT NULL', $field, UnaryExpression::POSTFIX));
    }
public function isNotNull($field)
    {
        if (!($field instanceof ExpressionInterface)) {
            $field = new IdentifierExpression($field);
        }

        return $this->add(new UnaryExpression('IS NOT NULL', $field, UnaryExpression::POSTFIX));
    }
public function isNotNull ( $ field ) { if ( ! ( $ field instanceof ExpressionInterface ) ) { $ field = new IdentifierExpression ( $ field ) ; } return $ this -> add ( new UnaryExpression ( 'IS NOT NULL' , $ field , UnaryExpression :: POSTFIX ) ) ; }
Adds a new condition to the expression object in the form "field IS NOT NULL".

@param string|\Cake\Database\ExpressionInterface $field database field to be
tested for not null
@return $this
Adds a new condition to the expression object in the form field IS NOT NULL .