Python sqlalchemy 多表查询 没有外键

多表查询 没有外键

from sqlalchemy import and_

两张表

q = db.session.query(User, UserIn).join(UserIn, and_(User.id==UserIn.user_id, User.id == 4)).all()

三张表

q = db.session.query(User, UserIn, Supplier).join(UserIn, and_(User.id==UserIn.user_id, User.id == 4)).join(Supplier, and_(UserIn.supplier_id==Supplier.id)).all()

SELECT tb_supplier., tb_user., tb_user_belonging.* FROM tb_supplier, tb_user left JOIN tb_user_belonging ON tb_user.id = tb_user_belonging.user_id AND tb_user_belonging.supplier_id = tb_supplier.id AND tb_user.id = 4