Django中的游标是否在打开的事务中运行？ [英] Do cursors in Django run inside the open transaction?

问题描述

我的Django应用程序正在使用一些自定义SQL，该SQL在如下视图中执行：

My Django application is using some custom SQL which I am executing inside a view like this:

db = router.db_for_write(model)
cursor = connections[db].cursor()
cursor.execute("INSERT INTO ....")

由于我使用的是 TransactionMiddleware ，因此我的视图正在事务内运行，但是我不清楚是否能获得像这样的新游标会转义当前打开的事务，或者如果该游标仍是打开事务的一部分。我收到一些错误消息，使我相信游标正在事务中运行。

Since I am using the TransactionMiddleware, my view is running inside a transaction, but I'm not clear if getting a new cursor like this "escapes" the currently open transaction or if the cursor is still a part of the open transaction. I am getting some error messages that lead me to believe that cursor is running inside the transaction.

我希望能够使用游标在 TransactionMiddleware 。

I would like to be able to use a cursor to execute SQL commands outside of the transaction that was opened by the TransactionMiddleware. Is this possible?

如果重要的话，我正在PostgreSQL 8.4数据库上运行Django 1.4。

If it matters, I am running Django 1.4 with a PostgreSQL 8.4 database.

推荐答案

如果有一个要手动管理事务的视图，则应在该视图中使用装饰器手动提交。

If there is a view in which you want to manage the transaction manually, you should use the decorator in that view to commit_manually.

来自文档。

from django.db import transaction

@transaction.commit_manually
def viewfunc(request):
    ...
    # You can commit/rollback however and whenever you want
    transaction.commit()
    ...

    # But you've got to remember to do it yourself!
    try:
        ...
    except:
        transaction.rollback()
    else:
        transaction.commit()

@transaction.commit_manually(using="my_other_database")
def viewfunc2(request):
    ....

是的，导入事务游标仅提供事务的游标，而不会创建新的事务。

And yes, importing a transaction cursor only provides the the cursor of the transaction, and does not create a new transaction.

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