SELECT * FROM t1 UNION SELECT * FROM t2
SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2
SELECT * FROM t1 INTERSECT SELECT * FROM t2
SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
第1题:
A.REVOKE DROP ON t1 FROM PUBLIC
B.REVOKE UPDATE ON t1 FROM PUBLIC
C.REVOKE DELETE ON t1 FROM PUBLIC
D.REVOKE CONTROL ON t1 FROM PUBLIC
第2题:
A.SELECT * FROM T1 MINUS SELECT * FROM T2
B.SELECT * FROM T1 EXCEPT SELECT * FROM T2
C.SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1
D.SELECT * FROM T1 NOT EXISTS SELECT * FROM T2
第3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)
第4题:
存在两个结构相同的数据库表T1(col1,col2,col3)、T2(col1,col2,col3),写出一SQL语句将所有T1数据导入到T2表()
第5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?()
第6题:
The following statements:CREATE TABLE t1 (col1 INT NOT NULL, PRIMARY KEY(col1)); CREATE TABLE t2 (col1 INT NOT NULL, col2 CHAR(1) NOT NULL, PRIMARY KEY (col1, col2), FOREIGN KEY (col1) REFERENCES t1 (col1) ON DELETE CASCADE ON UPDATE RESTRICT); CREATE TABLE t3 (col1 INT NOT NULL, col2 INT NOT NULL, PRIMARY KEY (col1, col2),FOREIGN KEY (col1) REFERENCES t1 (col1) ON DELETE NO ACTION ON UPDATE RESTRICT);INSERT INTO t1 VALUES (1), (2); INSERT INTO t2 VALUES (1, ‘a‘), (1, ‘b‘), (2,‘c‘); INSERT INTO t3 VALUES (1, 100), (2, 200), (2,300);How many rows will be deleted by the following DELETE statement? DELETE FROM t1 WHERE col1= 1;()
A.4
B.3
C.1
D.0
第7题:
A.GRANT SELECT ON T1 TO U2
B.SELECT*FROM T1
C.SELECT c1 FROM T1
D.SELECT c1.c2 FROM T1
第8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)
第9题:
A view is created with the following statement:CREATE VIEW v1 AS SELECT col1, col2, col3, col4 FROM t1 WHERE col4 > 1000 WITH CHECK OPTIONWhat is the effect of the CHECK OPTION clause?()
第10题:
Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 5 4 5 2 5 5 Table T2: C1 C2 5 1 5 2 5 3 Which of the following queries will return only those rows that exist in T1 and not in T2?()