retry_interval): def _run_with_retries(fn, context, cursor_obj, statement, *arg, **kw): for retry in range(num_retries + 1): try: fn(cursor_obj, statement, context=context, *arg) except engine.dialect.dbapi.Erro
# works with all SQLAlchemy versions and all types of polymorphic # aliasing. paliased = aliased(Person) sess.query(paliased.name).filter( sess.query(Company.name) .filter(Company.company_id == paliased.company_id) .correlate(paliased) .as_scalar() == "Elbonia, Inc." ) aliased() 构...
参数(Parameters):propagate=False– 当为 True 时,事件监听器应应用于所有继承映射器和/或继承类的映射器,以及任何作为此监听器目标的映射器。 raw=False– 当为 True 时,传递给适用事件监听器函数的“target”参数将是实例的InstanceState管理对象,而不是映射实例本身。 retval=False –当为 True 时,用户定义的...
retry_interval):def _run_with_retries(fn, context, cursor_obj, statement, *arg, **kw):for retry in range(num_retries + 1):try:fn(cursor_obj, statement, context=context, *arg)except engine.dialect.dbapi.Error as raw_dbapi_err:connection = context.root_connectionif engine.dialect.is_di...
parameters, context, executemany): conn.info.setdefault('query_start_time', []).append(time.time()) logger.debug("Start Query: %s", statement) @event.listens_for(Engine, "after_cursor_execute") def after_cursor_execute(conn, cursor, statement, ...
context.dialect.do_execute, context, cursor_obj, statement, parameters )returne 给定上述方案,可以使用以下概念验证脚本演示事务中的重新连接。运行一次后,它将每五秒向数据库发出一个SELECT 1语句: fromsqlalchemyimportcreate_enginefromsqlalchemyimportselectif__name__ =="__main__": ...
parameters, context, executemany): conn.info.setdefault('query_start_time', []).append(time.time()) logger.debug("Start Query: %s", statement) @event.listens_for(Engine, "after_cursor_execute") def after_cursor_execute(conn, cursor, statement, ...
(3, '物理', 1)) raw_connection raw_connection from sqlalchemy import create_engine engine = create_engine( "mysql+pymysql://root:root1234@127.0.0.1:3306/code_record?charset=utf8", max_overflow=0, pool_size=5, ) def test(): conn = engine.contextual_connect() with conn: cur = conn...
Like books, the attribute publishers indicates a collection of publishers associated with an author. The first parameter, "Publisher", informs SQLAlchemy what the related class is. The second and third parameters are secondary=author_publisher and back_populates="authors": secondary tells SQLAlchemy...
DECLARE @parameters TABLE (ParameterName VARCHAR(100)) INSERT INTO @parameters VALUES('par1') INSERT INTO @parameters VALUES('par2') SELECT * FROM @parameters This creates rows, but still results in the no rows error. So I can't use INSERT anywhere in my query?