单项选择题
A. SELECT last_name FROM EMP WHERE last_name LIKE ‘_A%’;
B. SELECT last_name FROM EMP WHERE last name =’*A%’
C. SELECT last_name FROM EMP WHERE last name =’_A%’;
D. SELECT last_name FROM EMP WHERE last name LIKE ‘*A%’
多项选择题 Which two statements about subqueries are true? （）
单项选择题 Examine these statements: CREATE ROLE registrar GRANT UPDATE ON dtudent_grades TO registrar; GRANT registrar to user1, user2, user3; What does this set of SQL statements do?（）
单项选择题 Examine the data from the ORDERS and CUSTOMERS tables. Evaluate the SQL statement: What is the result when the query is executed?（）