IBM(000-730)章節(jié)練習(2019.03.13)

The EMPLOYEE table contains the following information: EMPNO NAME WORKDEPT
101 SAM A11 102 JOHN C12 103 JANE -104 PAT Remote
105 ANNE -106 BOB A11
The MANAGER table contains the following information: MGRID NAME DEPTNO EMPCOUNT
1 WU B01 - 2 JONES A11 - 3 CHEN - - 4 SMITH - -5 THOMAS C12 -
After this statement is executed: UPDATE manager m SET empcount = (SELECT COUNT(workdept) FROM employee e WHERE workdept=m.deptno)
What is the result of the following query?（）
SELECT mgrid, empcount FROM MANAGER WHERE empcount IS NOT NULL ORDER BY mgrid

Given the following requirements:
Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table.
Which of the following CREATE statements will successfully create this table?（）