吉林大学《数据库应用技术》在线作业一答卷

1、吉大18春学期数据库应用技术在线作业一-0001试卷总分:100 得分:100一、单选题 (共 25 道试题,共 100 分)Given the tables: COUNTRY STAFF id name person cities id name 1 Argentina 1 10 1 Aaron 2 Canada 2 20 2 Adams 3 Cuba 2 10 3 Jones 4 Germany 1 0 5 France 3 5 6 Italy 1 5 the report: id name number_of_countries - - - 1 Aaron 3 and the SQL s

2、tatement: SELECT B.id,B.name,COUNT(DISTINCT A.name) AS number_of_countries FROM country A, staff B WHERE B.id=A.person GROUP BY B.id,B.name HAVING COUNT(DISTINCT A.name):count_var Which of the following values does :count_var require to print out the above report?1234答案:B2.两个子查询的结果（），可以执行并、交、差操作结构完全

3、一致结构完全不一致结构部分一致主键一致答案:A3.对于支持小规模的部门级应用，这些应用不需要存取驻留在OS/400、OS/390等平台上的远程数据库，则需要哪种级别的DB2 产品？企业版工作组版企业扩展版个人版卫星版微型版答案:B4.Given an ODBC/CLI program with a single connection, two threads and the following actions which complete successfully: Thread 1: INSERT INTO mytab VALUES (1) Thread 2: INSERT INTO myt

4、ab VALUES (2) Thread 1: COMMIT Thread 2: INSERT INTO mytab VALUES (3) Thread 1: ROLLBACK Thread 2: COMMIT How many records will be inserted and retained in the table MYTAB?0123答案:C5.在数据库中存储的是：（）数据数据模型数据以及数据之间的联系信息答案:C6.使用DROP语句撤消基本表时，使用以下哪个子句，可以将下属的视图和约束引用全部撤消？NULLRESTRICTCASCADEDISTINCT答案:C7.关系模式中各

5、级模式之间的关系为（）3NF包含 2NF包含 1NF3NF包含 1NF包含 2NF1NF 包含2NF包含 3NF2NF包含 1NF 包含3NF答案:A8.在语句CREATE VIEW EMP_VIEW2 (EMPNO, EMPNAME, DEPTNO, JOBTITLE, HIREDATE) AS SELECT ID, NAME, DEPT, JOB, HIREDATE FROM EMPLOYEE WHERE DEPT=10 WITH CHECK OPTION; 所定义的视图中，当使用INSERT语句时，若新增的行中DEPTNO数值不为10，则该行将被拒绝插入。正确错误答案:A9.若用如下的S

6、QL语句创建一个student表： CREATE TABLE student(NO CHAR（4） NOT NULL， NAME CHAR（8） NOT NULL， SEX CHAR（2）， AGE NUMBERIC（2） 可以插入到student表中的是哪一项？（1031，曾华，男，23）（1031，曾华，NULL，NULL）（NULL，曾华，男，23）（1031，NULL，男，23）答案:B10.Given the following table: CREATE TABLE employee (name CHAR(10), salary DEC NOT NULL WITH DEFAULT)

7、 INSERT INTO employee (name, salary) VALUES (SMITH, 30000) INSERT INTO employee (name) VALUES (JONES) INSERT INTO employee (name, salary) VALUES (ALI, 35000) Which of the following statements will retrieve more than one row?SELECT salary FROM employee WHERE salary IN (SELECT (salary/(SELECT SUM(sala

8、ry) FROM employee) FROM employee)SELECT COALESCE(AVG(salary) FROM employeeSELECT SUM(salary)/COUNT(*) FROM employeeSELECT salary/(SELECT SUM(salary) FROM employee) FROM employee答案:D11.并发控制的主要方法是采用以下哪种机制？口令锁副本检查点答案:B12.E-R图中的联系可以与（）实体有关0个1个1个或多个多个答案:C13.下述关于数据库系统的正确叙述是（）数据库中只存在数据项之间的联系数据库的数据项之间和记录之间都

9、存在联系数据库的数据项之间无联系，记录之间存在联系数据库的数据项之间和记录之间都不存在联系答案:B14.定义基本表时，若要求某一列的值不能为空，则应在定义时使用什么保留字？但如果该列是主键，则可省写。NULLNOT NULLDISTINCTUNIQUE答案:B15.SQL语言具有（）功能。关系规范化、数据操纵、数据控制数据定义、数据操纵、数据控制数据定义、关系规范化、数据控制数据定义、关系规范化、数据操纵答案:B16.创建一个DMS类型的表空间，可以使用以下哪两种文件系统对象作为容器？目录文件DEVICE答案:B17.发人员开发访问后台AIX上的DB2的windows程序，需要在windows

10、开发平台上安装：DB2运行时间客户端DB2管理客户端DB2应用程序开发客户端DB2瘦客户端答案:C18.Given the expression: WITH most_cities AS ( SELECT b.id,,a.cities FROM country a, staff b WHERE a.person = b.id AND cities :threshold ) SELECT * FROM most_cities In which of the following does MOST_CITIES exist?user tablesserver memoryuser ta

11、ble spacesystem catalog tables答案:B19.下列哪种工具可以向表中增添记录，并更改数据库的统计信息？importinsertloadupdate答案:C20.Under which of the following situations must dynamic SQL be used?When temporary table references exist at compile timeWhen the host variables values are unknown at compile timeWhen the columns in the SELECT

12、 clause are unknown at compile timeWhen the number of rows being returned are unknown at compile time答案:C21.How many rows can be retrieved using a single SELECT INTO statement?Only one rowAs many as are in the resultAs many as are host variables used in the callAs many as host variable array structu

13、res can hold答案:A22.下面哪个工具可以保存终端用户需要存取的元数据？Query Management FacilityDB2 Query PatrollerDB2存储过程构建器信息目录答案:D23.要更改数据库管理器配置文件，需以下哪个数据库权限？DBADMSYSMAINTSYSCTRLSYSADM答案:D24.下列那种隔离级对于只读操作不在数据行上加锁？RRRSCSUR答案:D25.Given the EMPLOYEE table definition: CREATE TABLE employee ( workdept CHAR(30), salary INTEGER ) Which of the following is a correct usage of parameter markers in a JDBC program?String sql = UPDATE employee SET salary=salary*?WHERE workdept=?; statement stmt=con.createStatement(sql);String sql = UPDATE employee SET salary=salary*?WHERE workdept=?; statement stmt=con.createStatement(s