is there a sample project available which combines exposed w kotlinlang #exposed

once things get complicated, e.g. trying to do one transaction across multiple repos, I tend to bump into various exceptions that seem to be caused by the transaction being bound to a ThreadLocal rather than a coroutine context...

waltermcq

12/02/2020, 11:24 PM

you may want to try the #spring channel, and also #coroutines

👍 1

Joel

12/03/2020, 5:18 AM

@Tristan Blakers that's my tooling. Basically use

newSuspendedTransaction

instead of

transaction

in a coroutine context.

Tristan Blakers

12/03/2020, 5:28 AM

Thanks for replying! I tried using newSuspendedTransaction but ran into the same issues. Reading through the source code, it's not clear to me how this could work with Spring, as currently implemented

reason being that in the SpringTransactionManager provided by Exposed, it ultimately calls

Copy code

override fun currentOrNull(): Transaction? = TransactionSynchronizationManager.getResource(this) as Transaction?

which calls into Spring's TransactionSynchronizationManager, which stores the current transaction state in a Threadlocal

Joel

12/03/2020, 8:07 PM

I see. I only use the transaction manager in blocking contexts. It should still be able to open a transaction on the thread in which the function is executed, but any suspend points within that function may have issues.

@Tristan Blakers what I've done as a general solution (and to get around the default-db-is-the-last-one issue) is injecting a

Database

connection that wraps my Hikari datapool, and then call Exposed natively from there.

We also use Axon Framework for CQRS and the SpringTransactionManager plays really well with that.

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