I face some trouble with IBM DB2's auto-increment columns. At first, all my columns were defined as GENERATED ALWAYS, but since I had trouble with this when using
the "db2 import ..." command, I changed them to GENERATED BY DEFAULT. This is necessary, sinceI need
the IDs to be consistent, because other tables reference them. So using "db2 import ... modified by identityignore ..." isn't an option.
When I now import data,
the IDs are inserted correctly, but everytime I do this, I have to remember to set a new start for
the auto-increment column by getting
the highest Id+1 and alter
the column like this:
SELECT MAX(mycolumn)+ 1 FROM mytable;
ALTER TABLE mytable ALTER COLUMN mycolumn RESTART WITH <above_result>;
If I forget this, an Insert-Statement will fail with an duplicate PK error, since
the auto-increment column is
the primary key.
So my question is:
Is there a way to find
the next value for an auto-increment column, so I could write Statements that would check, if this value is less then
the SELECT MAX and needs to be set?
Or:
Isn't this whole thing as complicated as it seems to me? Could I somehow import data, preserving
the IDs and have
the auto-increment column still working as expected?
