多项选择题
A. SELECT TOTAL(*) FROM customer;
B. SELECT COUNT(*) FROM customer;
C. SELECT TOTAL(customer_id) FROM customer;
D. SELECT COUNT(customer_id) FROM customer;
E. SELECT COUNT(customers) FROM customer;
F. SELECT TOTAL(customer_name) FROM customer;
多项选择题 Examine the data from the EMP table: EMP_ID DEPT_ID COMMISSION 1 10 500 2 20 1000 3 10 4 10 600 5 30 800 6 30 200 7 10 8 20 300 The COMMISSION column shows the monthly commission earned by the employee. Which three tasks would require subqueries or joins in order to perform in a single step? （）
多项选择题 Which four statements correctly describe functions that are available in SQL? （）
单项选择题 Examine the structure if the EMPLOYEES table: You need to create a view called EMP_VU that allows the user to insert rows through the view. Which SQL statement, when used to create the EMP_VU view, allows the user to insert rows?（）