lib/Sirel/Visitor/ToSql.php
protected function visitSirelNodeEqual(Node\Equal $equal)
    {
        $left  = $this->visit($equal->getLeft());
        $right = $equal->getRight();

        if ($right === null) {
            return $left . ' IS NULL';
        } else {
            return $left . ' = ' . $this->visit($right);
        }
    }
protected function visitSirelNodeEqual(Node\Equal $equal)
    {
        $left  = $this->visit($equal->getLeft());
        $right = $equal->getRight();

        if ($right === null) {
            return $left . ' IS NULL';
        } else {
            return $left . ' = ' . $this->visit($right);
        }
    }
protected function visitSirelNodeEqual ( Node \ Equal $ equal ) { $ left = $ this -> visit ( $ equal -> getLeft ( ) ) ; $ right = $ equal -> getRight ( ) ; if ( $ right === null ) { return $ left . ' IS NULL' ; } else { return $ left . ' = ' . $ this -> visit ( $ right ) ; } }
Transform to SQL Equality, if the right operand is NULL,
then an "IS NULL" comparison is generated.

@param  Node\Equal $equal
@return string
Transform to SQL Equality if the right operand is NULL then an IS NULL comparison is generated .