How to parse EXTRACT(MINUTE FROM datetime1 - datetime2)

[yuchaofan13]

I think the solution would be to modify parse_from if FROM is preceded by 'EXTRACT(foobar '.

[georgesittas]

Sqlglot already parses extract(minute from datetime1). The problem is with the subtraction, because _parse_extract currently parses the part after from using _parse_type. If you use a more general parser method, it'll work just fine.

[yuchaofan13]

Got it working, thank you!!

from sqlglot import parse_one, exp
from sqlglot.parser import Parser
from sqlglot.tokens import Tokenizer, TokenType
def _parse_extract(self):
    this = self._parse_var() or self._parse_type()

    if not self._match(TokenType.FROM):
        self.raise_error("Expected FROM after EXTRACT", self._prev)

    return self.expression(exp.Extract, this=this, expression=self._parse_bitwise())
Parser._parse_extract = _parse_extract

[georgesittas]

Cool! This seems like something worth supporting in general, so feel free to open a PR.

EDIT: fixed.