Message-ID: <gh-postgresql-interfaces-psqlodbc-116-c2896902434@github.com>
From: "markmaker (@markmaker)" <noreply+markmaker@github.com>
To: "postgresql-interfaces/psqlodbc" <noreply+postgresql-interfaces-psqlodbc@github.com>
Date: Wed, 21 May 2025 07:30:14 +0000
Subject: Re: [postgresql-interfaces/psqlodbc] issue #116: Understanding Transactions in ODBC
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Thanks @davecramer,

> There is a way to see if you are in a transaction

From outside the ODBC driver? How?

> Also you are correct this is how you control transactions

So to begin a transaction, I would

1. `SQLSetConnectAttr(... SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF ...);`
2. `SQLSetConnectAttr( ... SQL_ATTR_TXN_ISOLATION, SQL_TXN_SERIALIZABLE ...);`


To commit I would...

1. `SQLEndTran(... SQL_COMMIT);`
2. `SQLSetConnectAttr(... SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_ON ...);`
3. `SQLSetConnectAttr( ... SQL_ATTR_TXN_ISOLATION, SQL_TXN_READ_COMMITTED ...);`

Rollback the same but with `SQL_ROLLBACK` in the first call.

### Error handling

If I can't commit (deadlock etc.) then it is _implicitly_ a rollback, right? Or should I then call  `SQLEndTran(... SQL_ROLLBACK)` to be on the safe side? 

I any case, I would still continue with 2. and 3. 

_Mark