How would you add a foreign key constraint on the dept_no column in the EMP table, referring to the id column in the DEPT table?
Answer options
A
Use the ALTER TABLE command with the ADD clause on the EMP table.
B
Use the ALTER TABLE command with the MODIFY clause on the EMP table.
C
Use the CREATE TABLE command with the FOREIGN KEY clause.
D
Use the DROP TABLE command and recreate the table.
Correct answer: Use the ALTER TABLE command with the ADD clause on the EMP table.
Explanation
ALTER TABLE EMP ADD CONSTRAINT fk_dept FOREIGN KEY (dept_no) REFERENCES dept(dept_no);