Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?
Correct; you cannot truncate a table which has an FK constraint on it.
Typically my process for this is:
- Drop the constraints
- Trunc the table
- Recreate the constraints.
(All in a transaction, of course.)
Of course, this only applies if the child has already been truncated. Otherwise I go a different route, dependent entirely on what my data looks like. (Too many variables to get into here.)
The original poster determined WHY this is the case; see this answer for more details.
DELETE FROM TABLENAMEDBCC CHECKIDENT ('DATABASENAME.dbo.TABLENAME',RESEED, 0)Note that this isn't probably what you'd want if you have millions+ of records, as it's very slow.
Because TRUNCATE TABLE is a DDL command, it cannot check to see whether the records in the table are being referenced by a record in the child table.
This is why DELETE works and TRUNCATE TABLE doesn't: because the database is able to make sure that it isn't being referenced by another record.