(Node.data == "subchild1") .join(Node.parent.of_type(nodealias)) .where(nodealias.data == "child2") ).all() SELECT node.id AS node_id, node.parent_id AS node_parent_id, node.data AS node_data FROM node JOIN node AS node_1 ON node.parent_id = node_1.id WHERE node.data...
此深度设置通过`relationships.join_depth`进行配置: ```py class Node(Base): __tablename__ = "node" id = mapped_column(Integer, primary_key=True) parent_id = mapped_column(Integer, ForeignKey("node.id")) data = mapped_column(String(50)) children = relationship("Node", lazy="joined", ...
def queryByJoin(): """ 连接查询""" with getSession() as session: # ---方式一: 同时查询多张表 --- query = session.query(YmUser, YmUserInfo).filter(YmUser.id == YmUserInfo.uid, YmUser.id < 50) query = query.filter(YmUser.id == YmUserInfo.uid, YmUser.id < 50) result = qu...
3. Output: Execution of the command above will result in rows from the table_1 along with rows which satisfies the condition from table_2 Output: Execution of the command above will result in rows from the table_2 along with rows which satisfies the condition from table_1. LEFT JOIN,RIGHT...
# SQLAlchemy 1.4 / 2.0 cross compatible use stmt = select(User).join(User.addresses) result = session.execute(stmt) stmt = select(User).options(joinedload(User.addresses)) result = session.execute(stmt) stmt = select(Address).where(with_parent(u1, User.addresses)) result = session.execute...
def queryByJoin(): """ 连接查询""" with getSession() as session: # ---方式一: 同时查询多张表 --- query = session.query(YmUser, YmUserInfo).filter(YmUser.id == YmUserInfo.uid, YmUser.id < 50) query = query.filter(YmUser.id == YmUserInfo.uid, YmUser.id < 50) result = qu...
from sqlalchemy.future import select stmt = select(User, Address).join(User.addresses) for row in session.execute(stmt).mappings(): print("the user is: %s the address is: %s" % (row[User], row[Address])) 另请参阅 RowProxy 不再是“代理”; 现在称为 Row,并且行为类似于增强型命名元组...
q = session.query(Address).filter(with_parent(u1, "addresses")) 迁移到2.0 现代SQLAlchemy 1.x版本支持推荐的使用映射属性的技术: # compatible with all modern SQLAlchemy versions q = session.query(User).join(User.addresses) q = session.query(User).options(joinedload(User.addresses)) ...
def queryByJoin(): """ 连接查询""" with getSession() as session: # ---方式一: 同时查询多张表 --- query = session.query(YmUser, YmUserInfo).filter(YmUser.id == YmUserInfo.uid, YmUser.id < 50) query = query.filter(YmUser.id == YmUserInfo.uid, YmUser.id < 50) result = qu...
select().join() 和 outerjoin() 将 JOIN 条件添加到当前查询中,而不是创建子查询 - 有些相关的是,Select类中的.join()和.outerjoin()方法隐式地创建了一个子查询,然后返回一个Join构造,这在大多数情况下是没有用的,会导致很多混乱。决定采用更加有用的 2.0 风格的连接构建方法,这些方法现在与 ORMQuery....