在sqlalchemy ORM查询中使用NOT EXISTS子句

Question

我想将以下原始sql查询转换为sqlalchemy ORM查询:

SELECT * FROM kwviolations AS kwviol WHERE kwviol.proj_id=1 AND NOT EXISTS (SELECT * FROM
kwmethodmetrics AS kwmetrics WHERE kwmetrics.kw_id=kwviol.kw_id AND kwmetrics.checkpoint_id=5);

我尝试了以下ORM查询但没有成功:

self.session.query(KWViolations).filter(KWViolations.proj_id==project.id).\
filter(and_(~KWViolations.kw_id.any(KWMethodMetrics.kw_id==KWViolations.kw_id),KWMethodMetrics.checkpoint_id==checkpoint.id))

有人可以帮忙吗？提前致谢

Answer 1

kw_id这里似乎是一个标量列值,所以你不能调用any()它 - any()只能从一个relationship()绑定属性中获得.由于我在这里没有看到其中一个,你可以直接调用exists():

from sqlalchemy import exists

session.query(KWViolations).filter(KWViolations.proj_id == project.id).\
    filter(
        ~exists().where(
                and_(
                    KWMethodMetrics.kw_id == KWViolations.kw_id,
                    KWMethodMetrics.checkpoint_id == checkpoint.id
                )
        )
    )