I have a DB2-database. Most of the tables have a primary key that is filled by selecting and updating a row from another table. (to mimic the Oracle Sequence-function).
"Select PrimKey from tPrimKeys where table="MyTable"; Update tPrimKeys set PrimKey=PrimKey+1 where table="MyTable""
When 2 users simultaniously try to insert a record into MyTable, they both select the same Primkey from the primkeys table, and they both try to insert a record into myTable with the same primary key. Which obviously results into a duplicate key-error.
So what can I do ? Is there any way of explicitly locking the table (and unlocking) to make sure that no-one gets a duplicate number ?