SQL> create table registrations
2 ( attendee NUMBER(4)
3 , course VARCHAR2(6)
4 , begindate DATE
5 , evaluation NUMBER(1)
6 , constraint R_PK primary key (attendee,course,begindate)
7 ) ;
Table created.
SQL>
SQL>
SQL>
SQL>
SQL> alter table registrations
2 drop column begindate;
drop column begindate
*
ERROR at line 2:
ORA-12991: column is referenced in a multi-column constraint
SQL>
SQL>
SQL> drop table registrations;
Table dropped.
SQL>
SQL>
SQL>