Why does SQLAlchemy session not execute SQL operations via its bounded connection? -


code:

import app flaskr  app = flaskr.app app.config.from_pyfile('config.py')  connection = flaskr.db.engine.connect() session = flaskr.db.create_scoped_session(     options=dict(bind=connection, binds={}))  obj = object(...) session.add(obj) session.commit()  """ debug:sqlalchemy.pool.queuepool:created new connection <_mysql.connection open '******' @ 208f590> info:sqlalchemy.engine.base.engine:show variables 'sql_mode' info:sqlalchemy.engine.base.engine:() info:sqlalchemy.engine.base.engine:() info:sqlalchemy.engine.base.engine:show collation `charset` = 'utf8' , `collation` = 'utf8_bin' info:sqlalchemy.engine.base.engine:() info:sqlalchemy.engine.base.engine:select cast('test plain returns' char(60)) anon_1 info:sqlalchemy.engine.base.engine:() info:sqlalchemy.engine.base.engine:select cast('test unicode returns' char(60)) anon_1 info:sqlalchemy.engine.base.engine:() info:sqlalchemy.engine.base.engine:select cast('test collated returns' char character set utf8) collate utf8_bin anon_1 info:sqlalchemy.engine.base.engine:() debug:sqlalchemy.pool.queuepool:connection <_mysql.connection open '******' @ 208f590> checked out pool debug:sqlalchemy.pool.queuepool:created new connection <_mysql.connection open '******' @ 20b45b0> debug:sqlalchemy.pool.queuepool:connection <_mysql.connection open '******' @ 20b45b0> checked out pool info:sqlalchemy.engine.base.engine:begin (implicit) ... info:sqlalchemy.engine.base.engine:commit debug:sqlalchemy.pool.queuepool:connection <_mysql.connection open '******' @ 20b45b0> being returned pool debug:sqlalchemy.pool.queuepool:connection <_mysql.connection open '******' @ 20b45b0> rollback-on-return """

i bind connection session, when commit new object, new connection created , used. why?!

doc:

bind – optional engine or connection session should bound. when specified, sql operations performed session execute via connectable.


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