How to parse CREATE IMMEDIATE efficiently?

[usmanovbf]

Hi!
Could you help me, please, and advice where and how to modify parsers and extra functionality to obtain EXECUTE IMMEDIATE for Trino https://trino.io/docs/current/sql/execute-immediate.html

It also available only for Starbust and Oracle AFAIK

It would be very helpful to point at the similar examples of the parsers which obtain keywords in the beginning of the statements as for EXECUTE IMMEDIATE

Thank you!

[georgesittas]

Hey 👋

You'd need to add an entry in STATEMENT_PARSERS, which will route to a new parser that produces a new Execute node. Or, if you don't really care about actually parsing it, you could treat it as a Command, e.g. by mapping EXECUTE to TokenType.COMMAND in Trino's Tokenizer class. Look into other statement parsers for reference.

[usmanovbf]

Sorry, I didn't get it. After entering to the _parse_execute() method, I expect that I need to match IMMEDIATE word and the cursor moves to the ' symbol where I can use _parse_string() method to capture the quoted statement. But instead of that,I get the self._curr as a whole rest of the string instead of matching then next IMMEDIATE word. And as you see on the screenshot, the cursor doesn't move after expected matching the IMMEDIATE word.

[georgesittas]

Ah that's right, it's because TokenType.EXECUTE is a COMMAND token, see tokens.py. That would have to be removed from that set.

[usmanovbf]

so, I am confused. If TokenType.EXECUTE should be removed, I don't know how to do it without any mistakes. Maybe you know. So, I have created Feature Request for that, please

[usmanovbf]

@georgesittas is there any process for removing that TokenType.EXECUTE from the set? You wrote that you and your team is not going to impelement that, so what do I need to do to remove TokenType.EXECUTE from the set and not to break any functionality? Without your explanation, I am stuck and afraid to make excess actions to submit non-valid PRs.

[georgesittas]

You can remove it from that set and implement the parsing logic as we discussed above. Don't worry too much about breaking stuff, we'll go over that when we review the PR if you make one, just focus on getting the parsing / generation logic in and keep in mind to gracefully handle error states so that we fall back to producing an exp.Command if we can't parse the input. Check out how we do this in _parse_create and _parse_alter, etc.