Table already has a primary key

Error constant SQLE_EXISTING_PRIMARY_KEY
ODBC 2 State 42000
ODBC 3 State 42000
Severity 16
SQLCODE –112
SQLSTATE 55013
Sybase error code 1923
Probable cause

You attempted to add a primary key on a table that already has a primary key defined. You must delete the current primary key before adding a new one.