SQL rollback of multiple inserts involving constraints

[Jacob Kruger]

Think performing a session/transaction flush after the first two inserts 
should offer the workaround before you've committed all transaction 
actions to the database finally:

https://medium.com/@oba2311/sqlalchemy-whats-the-difference-between-a-flush-and-commit-baec6c2410a9


HTH


Jacob Kruger
+2782 413 4791
"Resistance is futile!...Acceptance is versatile..."


On 2023/11/10 11:15, Loris Bennett via Python-list wrote:
> Hi,
>
> In my MariaDB database I have a table 'people' with 'uid' as the primary
> key and a table 'groups' with 'gid' as the primary key.  I have a third
> table 'memberships' with 'uid' and 'gid' being the primary key and the
> constraint that values for 'uid' and 'gid' exist in the tables 'people'
> and 'groups', respectively.  I am using SQLAlchemy and writing a method
> to setup a membership for a new person in a new group.
>
> I had assumed that I should be able to perform all three inserts
> (person, group, membership) with a single transaction and then rollback
> if there is a problem.  However, the problem is that if the both the
> insert into 'people' and that into 'groups' are not first committed, the
> constraint on the insertion of the membership fails.
>
> What am I doing wrong?
>
> Apologies if this is actually an SQL question rather than something
> related to SQLAlchemy.
>
> Cheers,
>
> Loris
>