You created an ORDERS table with the following description:
You inserted some rows in the table.
After some time, you want to alter the table by creating the PRIMARY KEY constraint on the
ORD_ID column.
Which statement is true in this scenario?
A.
You cannot have two constraints on one column.
B.
You cannot add a primary key constraint if data exists in the column.
C.
The primary key constraint can be created only at the time of table creation .
D.
You can add the primary key constraint even if data exists, provided that there are no duplicate values.