对于表A（col1 int，col2 char（1））更新col

A.Theoperationcol1.retainAll（col2）willnotmodifythecol1object.

B.Theoperationcol1.removeAll（col2）willnotmodifythecol2object.

C.Theoperationcol1.addAll（col2）willreturnanewcollectionobject，containingelementsfrombothcol1 andcol2.

D.Theoperationcol1.containsAll（Col2）willnotmodifythecol1object.

建立一个“职员”表，表中有5个字段：职员号、姓名、性别、年龄、部门。要求职员号属性的值惟一，并且不能为空值。建立该表的SQL语句可以是______。

A．CREATE TABLE职员(职员号CHAR(6)，姓名CHAR(8)，；性别CHAR(2)，年龄INT(4)，部门CHAR(12))

B．CREATE TABLE职员(职员号C1LAR(6) NULL，姓名 CHAR(8)，；性别CHAR(2)，年龄INT(4)，部门CHAR((12))

C．CREATE TABLE职员(职员号CHAR(6) NOT NULL UNIQUE，；姓名CHAR(8)，性别CHAR(2)，年龄INT(4)，部门CHAR(12))

D．CREATE TABLE职员(职员号CHAR(6)UNIQUE，姓名CHAR(8)，；性别CHAR(2)，年龄INT(4)，部门CHARR(12))

有以下程序：

include ＜iostream＞

using namespace std；

const xnt N=5；

int fun(char *s，char a，int n)

{

int j；

*s=a；j=n；

while(a＜s[j])

j--；

return j；

}

int main()

{

char s[N+1]；

int k；

YouworkwithadatabasenamedDB1，whichislocatedonaSQLServer2005computer.YoudiscoverthatatablescanonTable1inDB1causesaslowquery.Table1isaverylargetablethatisusedfrequently.Youascertainthatthequerycontainsthefollowingstatement.SELECTcol1，col2FROMtable1WHEREcol3=Youneedtoprovidemaximumqueryperformance.Table1mustremainavailabletousers.Whatshouldyoudo？（）

A.UpdateallstatisticsonTable1inDB1.

B.UsetheCREATESTATISTICSstatementinDB1tocreatemissingstatisticsoncol3ofTable1.

C.Setthepriorityboostserveroptionto1.

D.Executethefollowingstatement.USEDB1GOCREATEINDEXindex1ONtable1（col3）INCLUDE（col1，col2）WITH（ONLINE=ON）GO

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

建立一个学生信息表student，要求它由学号sno、姓名sname、性别sex、年龄age4个属性组成，其学号属性唯一，学号、姓名字段不能为空。下列语句正确的是

A．CREATE TABLE student(sno char(5) NOT NULL sname char(8) NOT NULL sex char(1) age int)；

B．CREATE TABLE student (sno char(5) NOT NULL UNIQUE sname char(8) sex char(1) age int)；

C．CREATE TABLE (sno char(5) NOT NULL UNIQUE sname char(8) NOT NULL sex char(1) age int)；

D．CREATE TABLE student (sno char(5) NOT NULL UNIQUE sname char(8) NOT NULL sex char(1) age int)；

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

A.更新DB1数据库中表Table1的所有统计信息

B.在DB1数据库中，使用CREATESTATISTICS语句为表Table1的列col3创建缺少的统计信息

C.设置优先值提升选项的值为1

D.执行如下语句：USEDB1GOCREATEINDEXindex1ONtable1（col3）INCLUDE（col1，col2）WITH（ONLINE=ON）GO

E.执行如下语句USEDB1GOCREATEINDEXindex1ONtable1（col3，col2，col1）

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