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Concurrency Issue with HSQLDB

Shunjie Liu
Greenhorn

Joined: Feb 21, 2006
Posts: 7
hello.
I am using IDENTITY to auto-generate my ID in one of my tables
and using CALL IDENTITY() to get back the newly created ID.

However, as I am doing this over a network. I noticed that my JDBC code
executes CALL INDENTITY() before my INSERT INTO ... statement is completed and thus returning the the incorrect ID.

when I put a sleep() for 5 sec, everything works fine. So I suppose its a problem with concurrency issue.

I am wondering is there any method to ensure when I call the CALL IDENTITY() function, it will return me the correct id ? A method that when updating the database, the CALL IDENTITY will be blocked before the INSERT statement is completed ?

Thank you
Kaydell Leavitt
Ranch Hand

Joined: Nov 18, 2006
Posts: 689

Here is my insert method. It works in single-user, I have not tried multi-user yet but I believe that it should work. This method makes a couple of assumptions: 1) only one record is inserted in the query, and 2) that the auto-generated key is a long (a BIGINT).


[ July 10, 2007: Message edited by: Kaydell Leavitt ]
Shunjie Liu
Greenhorn

Joined: Feb 21, 2006
Posts: 7
Thanks for the reply.

I am sure your code works for mySQL or other heavy weight database.
but this HSQLDB don't support that...oh well have to keep trying
 
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subject: Concurrency Issue with HSQLDB