单选题Given the following DDL and INSERT statements: CREATE VIEW v1 AS SELECT col1 FROM t1 WHERE col1 > 10; CREATE VIEW v2 AS SELECT col1 FROM v1 WITH CASCADED CHECK OPTION; CREATE VIEW v3 AS SELECT col1 FROM v2 WHERE col1 < 100; INSERT INTO v1 VALUES(5); IN

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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?（）

• A、Any row inserted or updated through view V1 must meet the condition that col4 > 1000.
• B、From now on, any row inserted or updated in table T1 must meet the condition that col4 > 1000, but existing rows in the table are not checked.
• C、At view creation, DB2 will check the data in table T1, and if in any row doesn't meet the condition col4 > 1000, the view creation will be rejected.
• D、Any row inserted or updated through view V1 must meet the condition that col4 > 1000 and no row in table T1 can be updated such that col4 <= 1000, but new rows in the table can be inserted with col4 <= 1000.

第6题：

设有关系模式商品（商品号，商品名称，单价，数量，类别），建立统计每类商品总数量的视图的正确语句是（）

• A、CREATE VIEW v1AS SELECT类别，SUM（数量）FROM商品GROUP BY类别
• B、CREATE VIEW v1AS SELECT类别，COUNT（数量）FROM商品GROUP BY类别
• C、CREATE VIEW v1（类别，总数量）AS SELECT类别，SUM（数量）FROM商品GROUP BY类别
• D、CREATE VIEW v1（类别，总数量）AS SELECT类别，COUNT（数量）FROM商品GROU PBY类别

第7题：

Given the following statements: CREATE TABLE tab1 (col1 INT); CREATE TABLE tab2 (col1 INT); CREATE TRIGGER trig1 AFTER UPDATE ON tab1 REFERENCING NEW AS new1 FOR EACH ROW MODE DB2SQL INSERT INTO tab2 VALUES(new1.col1); INSERT INTO tab1 VALUES(2),(3); What is the result of the following query? SELECT count(*) FROM tab2;（）

• A、3
• B、2
• C、1
• D、0

第8题：

You need to create a view EMP_VU. The view should allow the users to manipulate the records of only the employees that are working for departments 10 or 20.Which SQL statement would you use to create the view EMP_VU?（）

• A、CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20);
• B、CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH READ ONLY;
• C、CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH CHECK OPTION;
• D、CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20);
• E、CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) NO UPDATE;

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客服业务受到SQL语句的影响非常大，以下哪些是执行效率比较低的SQL语句，可以进行优化（）

• A、select*from record where substrb（CardNo，1，4）=’5378’；
• B、表tab1中的列col1是字符型（char），执行select col1，col2 from tab1 where col1>’10’；
• C、select count（*）from stuff where id_no in（’0’，’1’）；
• D、UPDATE SERVICEINFO SET STATE=0WHERE STATE<>0。

第17题：

Given the following DDL and INSERT statements: CREATE VIEW v1 AS SELECT col1 FROM t1 WHERE col1 > 10; CREATE VIEW v2 AS SELECT col1 FROM v1 WITH CASCADED CHECK OPTION; CREATE VIEW v3 AS SELECT col1 FROM v2 WHERE col1 < 100; INSERT INTO v1 VALUES(5); INSERT INTO v2 VALUES(5); INSERT INTO v3 VALUES(20); INSERT INTO v3 VALUES(100); How many of these INSERT statements will be successful?（）

• A、0
• B、1
• C、2
• D、3

第18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（）

• A、select col1，col2，col3 from T1 into T2（col1，col2，col3）
• B、insert T1 （col1，col，col3） into T2（col1，col2，col3）
• C、insert into T2 （col1，col2，col3） as select col1，col2，col3 from T1
• D、insert into T2（col1，col2，col3） select col1，col2，col3 from T1；

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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20题：

You need to create a view EMP_VU. The view should allow the users to manipulate the records of only the employees that are working for departments 10 or 20. Which SQL statement would you use to create the view EMP_VU? （）

• A、CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department _ id IN (10,20);
• B、CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH READ ONLY;
• C、CREATE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) WITH CHECK OPTION;
• D、CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WITH department_id IN (10,20);
• E、CREATE FORCE VIEW emp_vu AS SELECT * FROM employees WHERE department_id IN (10,20) NO UPDATE;

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