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.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2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3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4题:
Which of the following SQL statements will return the year and average salary for all employees hired within a given year that have a salary greater than $30,000?()
第5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;()
第6题:
Given the following two tables: TAB1 C1 C2 1 Antarctica 2 Africa 3 Asia 4 Australia TAB2 CX CY 5 Europe 6 North America 7 South America Which of the following SQL statements will insert all rows found in table TAB2 into table TAB1?()
第7题:
INSERT INTO tab1 SELECT cx, cy FROM tab2
INSERT INTO tab1 VALUES (tab2.cx, tab2.cy)
INSERT INTO tab1 VALUES (SELECT cx, cy FROM tab2)
INSERT INTO tab1 (c1, c2) VALUES (SELECT cx, cy FROM tab2)
第8题:
select col1,col2,col3 from T1 into T2(col1,col2,col3)
insert T1 (col1,col,col3) into T2(col1,col2,col3)
insert into T2 (col1,col2,col3) as select col1,col2,col3 from T1
insert into T2(col1,col2,col3) select col1,col2,col3 from T1;
第9题:
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10题:
4
3
1
0
第11题:
REVOKE DROP ON t1 FROM PUBLIC
REVOKE UPDATE ON t1 FROM PUBLIC
REVOKE DELETE ON t1 FROM PUBLIC
REVOKE CONTROL ON t1 FROM PUBLIC
第12题:
(难度:中等)已知表T1中有2行数据,T2中有3行数据,执行SQL语句“select a.* from T1 a,T2 b”后,返回的行数为6
答案:(yes)
第13题:
A.GRANT SELECT ON T1 TO U2
B.SELECT*FROM T1
C.SELECT c1 FROM T1
D.SELECT c1.c2 FROM T1
第14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15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?()
第16题:
Given the following two tables: TAB1 C1 C2 A 11 B 12 C 13 TAB2 CX CY A 21 C 22 D 23 The following results are desired: C1 C2 CX CY A 11 A 21 C 13 C 22 -- --D 23 Which of the following queries will yield the desired results?()
第17题:
Assuming PUBLIC has been granted all privileges on table T1, which of the following statements would continue to permit any user to add rows to table T1, but not remove them?()
第18题:
Consider this syntax: MERGE INTO t1 USING t2 ON (join predicate)….. What does the MERGE syntax do?()
第19题:
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20题:
It performs a merge join of the row from T2 only if it doesn’t exist in the T1 table.
It creates a natural join of tables T1 and T2 for all columns that have the same name.
It creates a Cartesian product of table T1 and table T2 for all columns that have the same name.
For each row from T2, it updates the row if it exists within table T1, otherwise it inserts the row into T1.
第21题:
INSERT INTO tab1 SELECT cx, cy FROM tab2
INSERT INTO tab1 VALUES (tab2.cx, tab2.cy)
INSERT INTO tab1 VALUES (SELECT cx, cy FROM tab2)
INSERT INTO tab1 (c1, c2) VALUES (SELECT cx, cy FROM tab2)
第22题:
SELECT * FROM T1 MINUS SELECT * FROM T2
SELECT * FROM T1 EXCEPT SELECT * FROM T2
SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1
SELECT * FROM T1 NOT EXISTS SELECT * FROM T2
第23题:
SELECT * FROM T1 MINUS SELECT * FROM T2
SELECT * FROM T1 EXCEPT SELECT * FROM T2
SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1
SELECT * FROM T1 NOT EXISTS SELECT * FROM T2