Thursday, May 9, 2013

Asynchronous file upload to an APEX_COLLECTION

If you are using asynchronous requests to upload data into an APEX_COLLECTION, you will end up with an ORA-00001: unique constraint violated (APEX_040100.WWV_FLOW_COLLECTION_MEMBERS_PK). The reason is simple, sometimes APEX tries to insert the same value (WWV_FLOW_COLLECTION_MEMBERS$.SEQ_ID). A workaround consist of managing queues on the server side.


Dan McGhan said...

Hey LG,

I missed this earlier. This is a strange problem that I don't think should be happening. I made a plug-in to Load CLOB values but it only uses a single Ajax request which makes it limited to the max size post allowed by the listener - usually around 2MB.

I was thinking about working around that limitation by splitting things up into multiple async requests. Sounds like I'm going to hit on this issue and attempt to come up with another solution as I can't depend on queues.

Thanks for the heads up!


Unknown said...

Hey Dan,

I will post about my current solution... :)