Database Reference
In-Depth Information
Figure 20.10
Primary and
Foreign Key
Constraints on
ARTISTS and
SONGS Tables.
In Figure 20.10, the USER_CONSTRAINTS query shows the primary
and foreign key constraints on the ARTISTS and SONGS tables created
above. Now go ahead and drop the ARTISTS table primary key with the
CASCADE option.
ALTER TABLE ARTISTS DROP PRIMARY KEY CASCADE;
Now we will use the USER_CONSTRAINTS query in Figure 20.10
once again to verify that the primary key has been removed from the
ARTISTS table and the related foreign key has been removed from the
Figure 20.11
Primary Key Drop
with Constraints
Cascade on the
ARTISTS Table.
