8.41. SQLAlchemy Query Exists

Important

• Exist

8.41.1. Exists

• https://docs.sqlalchemy.org/en/stable/orm/query.html#sqlalchemy.orm.Query.exists

✘

>>> q = session.query(User).filter(User.name == 'fred')
>>> session.query(q.exists())

SELECT EXISTS (
    SELECT 1 FROM users WHERE users.name = :name_1
) AS anon_1

✘

>>> session.query(User.id).filter(q.exists()).scalar()

✘

>>> from sqlalchemy import literal
>>> session.query(literal(True)).filter(q.exists()).scalar()