2:20 sct.edu.om -- Private III Question 14 Not yet answered Marked out of 0.50 Flag question Which of the following is the correct syntax for adding a PK constraint in an existing table? OG. ALTER TABLE tableName ADD CONSTRAINT constraint_name PRIMARY KEY; O b. ALTER TABLE tableName ADD PRIMARY KEY(columnName); C. ALTER TABLE tableName ADD CONSTRAINT constraint_name PRIMARY KEY(columnName); O d. ALTER TABLE tableName MODIFY CONSTRAINT constraint_name PRIMARY KEY(columnName); Previous page Next page Previous activity 9-Feb Video Lesson - DDL and DML Statements 2:181 sct.edu.om - Private III Question 15 Not yet answered Marked out of 0.50 P Flag question Which of the following SQL statements will remove all the employees whose does not have a salary in the WORKERS table? a. DROP FROM workers WHERE salary IS NOT NULL; b. DELETE FROM workers WHERE salary = NULL; C. DELETE FROM workers WHERE salary IS NOT NULL; d. DELETE * workers WHERE salary IS NULL; Previous page Next page Previous activity 19-Feb Video Lesson - DDL and DML Statements Jump to. 2:18 sct.edu.om - Private III Flag question Which of the following is the correct syntax for adding a PK constraint in an existing table? O a ALTER TABLE tableName ADD CONSTRAINT constraint_name PRIMARY KEY b. ALTER TABLE tableName ADD PRIMARY KEY(columnName): OC. ALTER TABLE tableName ADD CONSTRAINT constraint_name PRIMARY KEY(columnName); O d. ALTER TABLE tableName MODIFY CONSTRAINT constraint_name PRIMARY KEY(columnName); Previous page Next page Previous activity 19-Feb Video Lesson - DDL and DML Statements Jump to