第1题:
设有关系R(A,B,C)和S(C,D),与关系代数表达式ΠA,B,D(σR,C=S.C(R×S))等价的SQL语句是______。
A.SELECT*FROMR,S WHERE R.C=S.C
B.SELECT A,B,D FROM R,S WHERE R.C=S.C
C.SELECT A,B,D FROM R,S WHERE R=S
D.SELECT A,B FROM R WHERE(SELECT D FROM S WHERE R.C=S.
第2题:
已知有关系模式R(sno,sname,age),其中sno表示学生的学号,类型为Char(8),前4位表示入学年份。查询所有2003年入学的学生姓名(sname),SQL语句是 _______。
A.SELECT sname FROM R WHERE.sno='2003%'
B.SELECT sname FROM R WHERE sno LIKE '2003%'
C.SELECT sname FROM R WHERE sno='2003_'
D.SELECT sname FROM R WHERE sno LIKE '2003_'
第3题:
设有关系R(A,B,C) 和S(C,D) 与关系代数表达式πA,B,D(σR,C=s.c(R×S))
等价的SQL语句是
A.SELECT*FROM R,SWHERE R.C=S.C
B.SELECT A,B,D FROM R,S WHERE R.C=S.C
C.SELECT A,B,D FROM R,S WHERE R=S
D. SELECT A,B FROM R WHERE (SELECT D FROM S WHERE R.C= S.C)
第4题:
设有关系模式日(SC,SN,SA)、S(CP,CW),则SQL语句“SELECT*FORM. R UNION SELECT*FROM S”实现的功能是______。
A.RCS
B.RUS
C.R-S
D.R∞S
第5题:
Let's move from the general to the specific.This sentence means let’s talk about some particular and about some part, but not about the whole.
第6题:
Given the following two tables: TAB1 R1 A A A B B C C D E TAB2 R2 A A B B C C D Which of the following queries returns the following result set? RETVAL E()
第7题:
对
错
第8题:
demonstrate how greenhouses changed over time
contrast Italian and French forms of greenhouses
indicate the types of fruit that Europe once imported
present an example of a type of early greenhouse
show that greenhouses have been around for centuries
第9题:
Wooden
notched
armored
delicate
colorful
第10题:
Turn on auditing for objects in the Local Security Policy and Select 'Process Tracking'.
Turn on auditing for objects in the Local Security Policy and Select 'Object Access'.
Use Windows Explorer to turn on auditing for the specific files.
Have the administrator for domains log you on as an administrator and enable auditing for a specific file.
Turn on auditing for objects in the Local Security Policy and Select 'Account Management'.
Allow only one account at a time to log on to your shared folder. Check the event viewer to see who logged on.
第11题:
anticipates
articulates
makes light of
mocks
pays heed to
puts up with
第12题:
第13题:
已知有关系模式及(S_N0,S_NAME,AGE),其中S_NO表示学生的学号,类型为Char[8],前4位表示入学年份。查询所有2005年入学的学生姓名(S_NAME),SQL语句是(24)。
A.SELECT S_NAME FROM R WHERE S_NO = '2005% '
B.SELECT S_NAME FROM R WHERE S_NO LIKE '2005% '
C.SELECT S_NAME FROM R WHERE S_NO = '2005%'
D.SELECT S_NAME FROM R WHERE S_NO LIKE '2005%'
第14题:
在SQL Server 2008的某数据库中,设用户U1同时是角色R1和角色R2中的成员。现已授予角色R1对表T具有SELECT、INSERT和UPDATE权限,授予角色R2对表T具有INSERT和DENY UPDATE权限,没有对U1进行其他授权,则U1对表T有权执行的操作是( )。
A.SELECT和INSERT
B.INSERT、UPDATE和SELECT
C.SELECT和UPDATE
D.SELECT
第15题:
设有关系R(A,B,C)和S(C,D)。与关系代数表达式πA,B,D(σR.C=S.C(R×S)等价的SQL语句是
A.SELECT*FROM R,S WHERE R.C=S.C
B.SELECT A,B,D FROM R,S WHERE R.C=S.C
C.SELE4T 1,2,8 FROM R,S WHERE R=S
D.SELECT A,B FROM R WHERE(SELECT D FROM S WHERE R.C=S.
第16题:
第17题:
囚徒困境(prisoners’dilemma)
第18题:
You are a network administrator of an organization. Maria and John are your network assistant. You have grant then the rights to modify the user properties in the computer management. You want to audit the modification in user accounts. What should you do?()
第19题:
It being
Because it is
It is
Being that it is
Although it is
第20题:
第21题:
第22题:
SELECT r1 AS retval FROM tab1 INTERSECT SELECT r2 AS retval FROM tab2
SELECT r1 AS retval FROM tab1 EXCEPT SELECT r2 AS retval FROM tab2
SELECT DISTINCT r1 AS retval FROM tab1, tab2 WHERE r1 <> r2
SELECT r1 AS retval FROM tab1 UNION SELECT r2 AS retval FROM tab2
第23题: