Altering Primary Key constraint on a table i Oracle 10G

Question

Hi All,
Can anyone tell me how to alter a primary key constraint on any table. My concern is that, suppose i have a table called 'Employee' where only 'EmployeeName' is added as a primary ket constaint. Now i want to alter this P.K. constarint to add 'EmployeeName' and 'DateOfBirth' as a primary key. Can anyone suggest me how can i achieve that? Any help will be highly appreciated.

Answer 1

hi,
you need to drop the constraint and recreate it.
SQL> conn scott/tiger@alpspso
Connected.
SQL> create table test (id number constraint id_pk primary key,name varchar(30));
create table test (id number constraint id_pk primary key,name varchar(30))
ERROR at line 1:
ORA-00955: name is already used by an existing object
SQL> create table test_table (id number constraint id_pk primary key,name varchar(30))
Table created.
SQL> alter table test_table modify constraint id_pk primary key(id,name);
alter table test_table modify constraint id_pk primary key(id,name)
ERROR at line 1:
ORA-00933: SQL command not properly ended
SQL> alter table test_table modify constraint id_pk(id,name);
alter table test_table modify constraint id_pk(id,name)
ERROR at line 1:
ORA-00933: SQL command not properly ended
SQL> alter table test_table modify primary key(id,name);
alter table test_table modify primary key(id,name)
ERROR at line 1:
ORA-00933: SQL command not properly ended
SQL> alter table drop constraint id_pk;
alter table drop constraint id_pk
ERROR at line 1:
ORA-00903: invalid table name
SQL> alter table test_table drop constraint id_pk;
Table altered.
SQL> alter table test_table add constraint id_pk primary_key(id,name);
alter table test_table add constraint id_pk primary_key(id,name)
ERROR at line 1:
ORA-00902: invalid datatype
SQL> alter table test_table add constraint id_pk primary key(id,name);
Table altered.
Regards.
Navneet