多项选择题
A. A WHERE clause can be used to restrict both rows and groups.
B. A WHERE clause can be used to restrict rows only.
C. A HAVING clause can be used to restrict both rows and groups.
D. A HAVING clause can be used to restrict groups only.
E. A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.
F. A HAVING clause CANNOT be used in subqueries.
单项选择题 In which case would you use a FULL OUTER JOIN?（）
多项选择题 Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) Which three statements inserts a row into the table? （）
单项选择题 Evaluate the SQL statement: SELECT LPAD (salary,10,*) FROM EMP WHERE EMP _ ID = 1001; If the employee with the EMP_ID 1001 has a salary of 17000, what is displayed?（）