Wrong AST in self-joined query

[staabm]

I have the feeling the AST for a query like SELECT a.email, b.adaid FROM ada a LEFT JOIN ada b ON a.adaid=b.adaid is not correct.

        $queryString = 'SELECT a.email, b.adaid FROM ada a LEFT JOIN ada b ON a.adaid=b.adaid';

        // returns a Generator. will not parse anything if you don't iterate over it
        $commands = $parser->parse($queryString);

        foreach ($commands as list($command)) {
            // Parser does not throw exceptions. this allows to parse partially invalid code and not fail on first error
            if ($command instanceof SelectCommand) {
                $from = $command->getFrom();
                var_dump(get_class($from));
            }
        }

only output:

SqlFtw\Sql\Dml\TableReference\OuterJoin

I am wondering why the ast does not contain a TableReferenceTable in addition to the Join.
Also: I don't think OuterJoin is correct in this case.

[paranoiq]

hi. in SQL syntax JOINs are considered binary operators (simillarly to e.g. + in expressions). in this case operator OUTER JOIN has a left operand a and right operand b. if you inspect the OuterJoin object, there is $joinSide property saying what side the outer join is (LEFT|RIGHT) and both sides $left and $right are TableReferenceTable. one for a and the other for b:

btw, there are three types of expression trees in SQL:

• value expressions like e.g. 1 + foo(3),
• table/join expressions, and
• union/query expressions