使用 WHERE 在 SQLAlchemy Core 中批量更新 [英] Bulk update in SQLAlchemy Core using WHERE
本文介绍了使用 WHERE 在 SQLAlchemy Core 中批量更新的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我已经设法在 SQLAlchemy 中使用批量插入，例如:
I have managed to work with the bulk insert in SQLAlchemy like:
conn.execute(addresses.insert(), [
{'user_id': 1, 'email_address' : 'jack@yahoo.com'},
{'user_id': 1, 'email_address' : 'jack@msn.com'},
{'user_id': 2, 'email_address' : 'www@www.org'},
{'user_id': 2, 'email_address' : 'wendy@aol.com'},
])
我现在需要的是等价于更新的东西.我试过这个:
What I need now is something equivalent for update. I have tried this:
conn.execute(addresses.insert(), [
{'user_id': 1, 'email_address' : 'jack@yahoo.com', 'id':12},
{'user_id': 1, 'email_address' : 'jack@msn.com', 'id':13},
{'user_id': 2, 'email_address' : 'www@www.org', 'id':14},
{'user_id': 2, 'email_address' : 'wendy@aol.com', 'id':15},
])
期望每一行都根据 'id' 字段进行更新，但它不起作用.我假设是因为我没有指定 WHERE 子句，但我不知道如何使用字典中包含的数据指定 WHERE 子句.
expecting that each row gets updated according to the 'id' field, but it doesn't work. I assume that it is because I have not specified a WHERE clause, but I don't know how to specify a WHERE clause using data that is included in the dictionary.
有人可以帮我吗?
推荐答案
阅读 文档的插入、更新和删除部分.以下代码应该可以帮助您入门:
Read Inserts, Updates and Deletes section of the documentation. Following code should get you started:
from sqlalchemy.sql.expression import bindparam
stmt = addresses.update().
where(addresses.c.id == bindparam('_id')).
values({
'user_id': bindparam('user_id'),
'email_address': bindparam('email_address'),
})
conn.execute(stmt, [
{'user_id': 1, 'email_address' : 'jack@yahoo.com', '_id':1},
{'user_id': 1, 'email_address' : 'jack@msn.com', '_id':2},
{'user_id': 2, 'email_address' : 'www@www.org', '_id':3},
{'user_id': 2, 'email_address' : 'wendy@aol.com', '_id':4},
])
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