Обсуждение: Bug: Transaction still open after error when autocommit=true

Daniel Migowski <dmigowski@ikoffice.de> wrote:

> A small demo for the bug is attached.

The javadocs for Connection:

http://docs.oracle.com/javase/6/docs/api/java/sql/Connection.html

say:

| JDBC applications should use the appropritate Connection method
| such as setAutoCommit or setTransactionIsolation. Applications
| should not invoke SQL commands directly to change the connection's
| configuration when there is a JDBC method available.

I take that to mean that the right way to do this is to set
autoCommit to false and use the connection's commit() method.  If
you do it that way, is there a problem?

-Kevin

Clearly the exception that is thrown when you try to rollback is that
autocommit is on.

I don't really see this as a bug.

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca



On Thu, Dec 22, 2011 at 6:29 PM, Kevin Grittner
<Kevin.Grittner@wicourts.gov> wrote:
> Daniel Migowski <dmigowski@ikoffice.de> wrote:
>
>> A small demo for the bug is attached.
>
> The javadocs for Connection:
>
> http://docs.oracle.com/javase/6/docs/api/java/sql/Connection.html
>
> say:
>
> | JDBC applications should use the appropritate Connection method
> | such as setAutoCommit or setTransactionIsolation. Applications
> | should not invoke SQL commands directly to change the connection's
> | configuration when there is a JDBC method available.
>
> I take that to mean that the right way to do this is to set
> autoCommit to false and use the connection's commit() method.  If
> you do it that way, is there a problem?
>
> -Kevin
>
> --
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On 23 December 2011 10:09, Daniel Migowski <dmigowski@ikoffice.de> wrote:

> If I send a statement with a BEGIN token

Don't do that; the driver is expecting you to manage transaction
demarcation by using JDBC's autocommit setting and commit/rollback,
not by sending explicit SQL. (Kevin pointed out the relevant JDBC
javadoc that covers this in his reply)

If you must send a raw BEGIN for some reason, then you're also
responsible for transaction cleanup yourself (i.e. don't expect
commit() or rollback() to work; you must send appropriate SQL yourself
to commit or rollback the transaction)

The driver's implementation of autocommit boils down to "if autocommit
is off and the connection does not have an active transaction, then
send BEGIN before the next query". When autocommit is on, the driver
just assumes the server's default behavior - i.e. autocommit happens
without any special intervention. If you send an explicit transaction
demarcation commands, you'll confuse that.

Oliver