Bug #34093 with rewriteBatchedStatements, getGeneratedKeys returns them in ascending order
Submitted: 27 Jan 20:11 Modified: 1 Mar 13:33
Reporter: Eric Jensen
Status: Closed
Category:Connector/J Severity:S2 (Serious)
Version:5.1.5 OS:Any
Assigned to: Target Version:

[27 Jan 20:11] Eric Jensen 
Description:
Without rewriteBatchedStatements turned on, calling getGeneratedKeys() after an
executeBatch() will return the keys generated in order of the statements added using
addBatch.  

With rewriteBatchedStatements=true, however, getGeneratedKeys() returns the keys from an
executeBatch() in ascending key order.  This makes it impossible to map the generated keys
to the statements you ran, which effectively makes that call useless at best, and
misleading at worst.  

How to repeat:
Turn on rewriteBatchedStatements=true, executeBatch() some statements that follow the
pattern:

insert into test (uniqueTextKey) values (?)
on duplicate key UPDATE autoIncId = last_insert_id( autoIncId )

then look at the output of getGeneratedKeys()

Suggested fix:
It would be nice if getGeneratedKeys() with rewriteBatchedStatements=true worked, as it
can be a performance improvement over doing them individually.  But it would be preferable
for it to fail than to return them in arbitrary order.
[31 Jan 7:25] Bugs System 
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/41478
[31 Jan 7:41] Bugs System 
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/41479
[1 Mar 13:33] MC Brown 
A note has been added to the 5.1.6 changelog: 

Statements with batched values do not return correct values for getGeneratedKeys() when
rewriteBatchedStatements is set to true, and the statement has an ON DUPLICATE KEY UPDATE
clause.