单项选择题
A. ALTER TABLE table_name ENABLE constraint_name;
B. ALTER TABLE table_name STATUS = ENABLE CONSTRAINT constraint_name;
C. ALTER TABLE table_name ENABLE CONSTRAINT constraint_name;
D. ALTER TABLE table_name STATUS ENABLE CONSTRAINT constraint_name;
E. ALTER TABLE table_name TURN ON CONSTRAINT constraint_name;
单项选择题 Which syntax turns an existing constraint on?（）
单项选择题 Management has asked you to calculate the value 12*salary* commission_pct for all the employees in the EMP table. The EMP table contains these columns: Which statement ensures that a value is displayed in the calculated columns for all employees?（）
单项选择题 Examine the description of the EMPLOYEES table: Which statement shows the maximum salary paid in each job category of each department?（）