吉大19秋學(xué)期《數(shù)據(jù)庫應(yīng)用技術(shù)》在線作業(yè)一滿分哦 (2)

1、吉大 19 秋學(xué)期《數(shù)據(jù)庫應(yīng)用技術(shù)》在線作業(yè)一 -0001試卷總分:100 得分:100一、 單選題 (共 25 道試題,共 100 分)1.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

2、France 3 5 6 Italy 1 5 the report: id name number_of_countries ---------- ---------- ------------------- 1 Aaron 3 and the SQL statement: SELECT B.id,B.name,COUNT(DISTINCT A.name) AS number_of_countries FROM country A, s

3、taff 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?A.1B.2C.3D.4正確答案:B2.兩個(gè)子查詢的結(jié)果（） ，可以執(zhí)行并、交、差操作A

4、.結(jié)構(gòu)完全一致B.結(jié)構(gòu)完全不一致C.結(jié)構(gòu)部分一致D.主鍵一致正確答案:A3.對(duì)于支持小規(guī)模的部門級(jí)應(yīng)用，這些應(yīng)用不需要存取駐留在 OS/400、OS/390 等平臺(tái)上的遠(yuǎn)程數(shù)據(jù)庫，則需要哪種級(jí)別的 DB2 產(chǎn)品？A.企業(yè)版B.工作組版C.企業(yè)擴(kuò)展版D.個(gè)人版E.衛(wèi)星版F.微型版正確答案:B4.Given an ODBC/CLI program with a single connection, two threads and the f

5、ollowing actions which complete successfully: Thread 1: INSERT INTO mytab VALUES (1) Thread 2: INSERT INTO mytab VALUES (2) Thread 1: COMMIT Thread 2: INSERT INTO mytab VALUES (3) Thread 1: ROLLBACK Thread 2: COMMIT How

6、many records will be inserted and retained in the table MYTAB?A.0B.1C.2D.3正確答案:B10.Given the following table: CREATE TABLE employee (name CHAR(10), salary DEC NOT NULL WITH DEFAULT) INSERT INTO employee (name, salary) VA

7、LUES ('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?A.SEL

8、ECT salary FROM employee WHERE salary IN (SELECT (salary/(SELECT SUM(salary) FROM employee)) FROM employee)B.SELECT COALESCE(AVG(salary)) FROM employeeC.SELECT SUM(salary)/COUNT(*) FROM employeeD.SELECT salary/(SELECT SU

9、M(salary) FROM employee) FROM employee正確答案:D11.并發(fā)控制的主要方法是采用以下哪種機(jī)制？A.口令B.鎖C.副本D.檢查點(diǎn)正確答案:B12.E-R 圖中的聯(lián)系可以與（）實(shí)體有關(guān)A.0 個(gè)B.1 個(gè)C.1 個(gè)或多個(gè)D.多個(gè)正確答案:C13.下述關(guān)于數(shù)據(jù)庫系統(tǒng)的正確敘述是（）A.數(shù)據(jù)庫中只存在數(shù)據(jù)項(xiàng)之間的聯(lián)系B.數(shù)據(jù)庫的數(shù)據(jù)項(xiàng)之間和記錄之間都存在聯(lián)系C.數(shù)據(jù)庫的數(shù)據(jù)項(xiàng)之間無聯(lián)系，記錄之間存在聯(lián)系D.