单项选择题
Click the Exhibit button to examine the data of the EMPLOYEES table. Evaluate this SQL statement:
SELECT e.employee_id "Emp_id", e.emp_name "Employee", e.salary, m.employee_id "Mgr_id", m.emp_name "Manager"
FROM employees e JOIN employees m ON (e.mgr_id = m.employee_id)
AND e.salary > 4000;
What is its output?（）
A.A
B.B
C.C
D.D
E.E
相关考题
-
多项选择题
For which two actions can you use the TO_DATE function? （）
A.convert any date literal to a date
B.convert any numeric literal to a date
C.convert any date to a character literal
D.format 'January 10 1999' for input
E.format '10-JAN-99' to 'January 10 1999' -
多项选择题
Evaluate the SQL statement: TRUNCATE TABLE DEPT;Which three are true about the SQL statement? （）
A.It releases the storage space used by the table.
B.It does not release the storage space used by the table.
C.You can roll back the deletion of rows after the statement executes.
D.You can NOT roll back the deletion of rows after the statement executes.
E.An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.
F.You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table. -
单项选择题
Evaluate the set of SQL statements: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set?（）
A.The DESCRIBE DEPT statement displays the structure of the DEPT table.
B.The ROLLBACK statement frees the storage space occupied by the DEPT table.
C.The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
D.The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.
