Structure of the ORDERITEMS table

-If the constraints on the ORDER# and ITEM# columns of the ORDERITEMS table were created as a PRIMARY constraint,and the actual constraint name is not known,which of the following commands can be used to delete the constraint?
A) ALTER TABLE orderitems DROP ALL CONSTRAINTS;
B) ALTER TABLE orderitems DELETE ALL CONSTRAINTS;
C) ALTER TABLE orderitems DROP PRIMARY KEY;
D) ALTER TABLE orderitems DELETE PRIMARY KEY;

Question

​Structure of the ORDERITEMS table
 
-If the constraints on the ORDER# and ITEM# columns of the ORDERITEMS table were created as a PRIMARY constraint,and the actual constraint name is not known,which of the following commands can be used to delete the constraint?​
A) ALTER TABLE orderitems DROP ALL CONSTRAINTS; 
B) ALTER TABLE orderitems DELETE ALL CONSTRAINTS; 
C) ALTER TABLE orderitems DROP PRIMARY KEY; 
D) ​ALTER TABLE orderitems DELETE PRIMARY KEY;

Quizplus · Accepted Answer

Option C is the correct command to be used to delete a primary key constraint on a table. The ALTER TABLE statement is used to modify the structure of a table, and the constraint to be removed is specified by the PRIMARY KEY keyword. Option A and B are incorrect because there is no DROP ALL or DELETE ALL CONSTRAINTS command in SQL. Option D is incorrect because the correct command to remove a primary key constraint is DROP PRIMARY KEY, not DELETE PRIMARY KEY.

​Structure of the ORDERITEMS Table

Structure of the ORDERITEMS Table