多项选择题
A. A subquery should retrieve only one row.
B. A subquery can retrieve zero or more rows.
C. A subquery can be used only in SQL query statements.
D. Subqueries CANNOT be nested by more than two levels.
E. A subquery CANNOT be used in an SQL query statement that uses group functions.
F. When a subquery is used with an inequality comparison operator in the outer SQL statement, the column list in the SELECT clause of the subquery should contain only one column.
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 Which view should a user query to display the columns associated with the constraints on a table owned by the user? （）
单项选择题 The user Alice wants to grant all users query privileges on her DEPT table. Which SQL statement accomplishes this? （）