单项选择题X 纠错
A.SELECT r1 AS retval FROM tab1 INTERSECT SELECT r2 AS retval FROM tab2
B.SELECT r1 AS retval FROM tab1 EXCEPT SELECT r2 AS retval FROM tab2
C.SELECT DISTINCT r1 AS retval FROM tab1, tab2 WHERE r1 <> r2
D.SELECT r1 AS retval FROM tab1 UNION SELECT r2 AS retval FROM tab2
你可能喜欢
单项选择题
A.0
B.1
C.2
D.3
单项选择题
A.SELECT * FROM t1 UNION SELECT * FROM t2
B.SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2
C.SELECT * FROM t1 INTERSECT SELECT * FROM t2
D.SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
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
A. MGRID EMPCOUNT ----- -------- 1 0 2 2 5 1
B. MGRID EMPCOUNT ----- -------- 1 0 2 2 3 0 4 0 5 1
C. MGRID EMPCOUNT ----- -------- 1 3 2 3 3 3 4 3 5 3
D. MGRID EMPCOUNT ----- -------- 1 0 2 2 3 2 4 2 5 1
单项选择题
A.The CONNECT statement
B.The first FETCH of a cursor
C.The BEGIN TRANSACTION statement
D.The first executable SQL statement
单项选择题
A.SELECT * FROM t1 UNION SELECT * FROM t2
B.SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2
C.SELECT * FROM t1 INTERSECT SELECT * FROM t2
D.SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
单项选择题
A.Row
B.Table
C.Scalar
D.Column
单项选择题
A.CALL increase_salary('A00')
B.VALUES increase_salary('A00')
C.CALL increase_salary('A00', ?)
D.VALUES increase_salary('A00', ?)
单项选择题
A.DELETE ALL FROM tab01 FOR CURRENT OF csr01
B.DELETE FROM tab01 FOR CURRENT csr01 WITH RS
C.DELETE * FROM tab01 WHERE CURRENT csr01 WITH CS
D.DELETE FROM tab01 WHERE CURRENT OF csr01 WITH RR
单项选择题
A.REVOKE SELECT FROM user2 ON TABLE org.tab1
B.REVOKE SELECT ON TABLE org.tab1 FROM user2
C.REVOKE READ ACCESS FROM user2 ON TABLE org.tab1
D.REVOKE READ ACCESS ON TABLE org.tab1 FROM user2