+541 THE REFERENTIAL OR UNIQUE CONSTRAINT name HAS BEEN IGNORED BECAUSE IT IS A DUPLICATE
Explanation
A FOREIGN KEY clause uses the same key and parent table as another FOREIGN KEY clause, or a UNIQUE clause uses the same column list as another UNIQUE or PRIMARY KEY clause. In either case, the duplicate clause is ignored.
name is either the foreign key name or the unique constraint name.
System action
DB2® continues processing.
Programmer response
If the duplication is an error, correct the statement and execute it again.
SQLSTATE
01543