No support for `ANY` and `ALL` use in `WHERE`

[SeanTroyUWO]

Seems like the parser only supports the use of ANY and ALL in SELECT, not WHERE.
This form seems to work:

SELECT ALL column_name(s)
FROM table_name
WHERE condition;

There's a test for it in tests/sqlparser_common.rs line: 1539
This does not supported:

SELECT column_name(s)
FROM table_name
WHERE column_name operator ALL
  (SELECT column_name
  FROM table_name
  WHERE condition); 

I'm not sure why this is the case. Please let me know if this is intentional. If not I can create a PR.

[SeanTroyUWO]

The defining factor might actually be the use of a subquery after ALL of ANY.

[SeanTroyUWO]

I think I have a good handle on the issue, can I submit a PR that adds or changes elements to enum Expr? This may be a breaking change.

[alamb]

Hi @SeanTroyUWO -- a PR would be most helpful

I am not totally sure what ALL and ANY mean in SQL, but here is one for adding something similar with UNION ALL: #915

[SeanTroyUWO]

Hi @SeanTroyUWO -- a PR would be most helpful

I am not totally sure what ALL and ANY mean in SQL, but here is one for adding something similar with UNION ALL: #915

Okay finally getting around to this. The issue is I might break code that depends on the current implementation of ALL and ANY. Is that okay?