单项选择题
A.UPDATE stock SET (status = NULL; quantity, price = 0) WHERE item LIKE S%
B.UPDATE stock SET (status, quantity, price) = (NULL, 0, 0) WHERE item LIKE S%
C.UPDATE stock SET status = NULL, SET quantity = 0, SET price = 0 WHERE item LIKE 'S%'
D.UPDATE stock SET (status = NULL), (quantity = 0), (price = 0) WHERE item LIKE S%
单项选择题 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
单项选择题 Which of the following will begin a new unit of work?（）
单项选择题 Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 1 4 1 3 1 2 Table T2: C1 C2 1 1 1 2 1 3 Which of the following queries will return only those rows that exist in both T1 and T2?（）