Estimating schedule activity costs involves developing an(69)of the costs of the resources needed to complete each schedule activity. Cost estimating includes identifying and considering various costing alternatives. For example, in most application areas, additional work during a design phase is widely held to have the potential for reducing the cost of the execution phase and product operations. The cost estimating process considers whether the expected savings can offset the cost of the additional design work. Cost estimates are generally expressed in units of(70)to facilitate comparisons both within and across projects.The(71 )describes the business need, justification, requirements, and current boundaries for the project. It provides important information about project requirements that is considered during cost estimating.
A.accuracy
B.approximation
C.specification
D.summary
第1题
B.CREATE VIEW ZG_view AS; SELECT 职工号,姓名 FROM 职工表
C.CREATE QUERY ZG_view; SELECT 职工号,姓名 FROM 职工表
D.CREATE QUERY ZG_view AS; SELECT 职工号,姓名 FROM 职工表
第2题
用SQL命令生成含有字段职工号、姓名的视图,下列语句正确的是______。
A.CREATE VIEW ZG w AS SELECT职工号,姓名FROM 职工
B.CREATE QUERY ZG w AS SELECT职工号,姓名FROM 职工
C.CREATE VIEW ZG w AS SELECT职工号,姓名
D.CREATE QUERY ZG w AS SELECT职工号,姓名
第3题
用SQL命令生成含有字段职工号、姓名的视图,下列语句正确的是______。
A.CREATE VIEW ZG w AS SELECT职工号,姓名FROM职工
B.CREATE QUERY ZG w AS SELECT职工号,姓名FROM职工
C.CREATE VIEW ZG w AS SELECT职工号,姓名
D.CREATE QUERY ZG w AS SELECT职工号,姓名
第4题
用SQL命令生成含有字段职工号、姓名的视图,下列语句正确的是 ______。
A.CREATE VIEW ZG_w AS SELECT职工号,姓名FROM职工
B.CREATE QUERY ZG_w AS SELECT职工号,姓名FROM职工
C.CREATE VIEW ZG w AS SELECT职工号,姓名
D.CREATE QUERY ZG_w AS SELECT职工号,姓名
第5题
A.CREATE VIEW xs_view AS; SELECT学号,姓名,年龄FROM学生表
B.CREATE VIEW xs_view; SELECT学号,姓名,年龄FROM学生表
C.CREATE VIEW xs_view AS; (SELECT学号,姓名,年龄FROM学生表)
D.CREATE VIEW xs_view; (SELECT学号,姓名,年龄FROM学生表)
第6题
“教师表”中有“职工号”“姓名”和“工龄”字段,其中“职工号”为主关键字,建立“教师表”的SQL命令是()。
A.CREATE TABLE教师表(职工号C(10)PRIMARY,姓名C(20),工龄I)
B.CREATE TABLE教师表(职工号C(10)FOREIGN,姓名C(20),工龄I)
C.CREATE TABLE教师表(职工号C(10)FOREIGN KEY,姓名C(20),工龄I)
D.CREATE TABLE教师表(职工号C(10)PRIMARY KEY,姓名C(20),工龄I)
第7题
“教师表”中有“职工号”“姓名”和“工龄”字段,其中“职工号”为主关键字,建立“教师表”的SQL命令是()。
A.CREATE TABLE教师表(职工号C(10)PRIMARY,姓名C(20),工龄I)
B.CREATE TABLE教师表(职工号C(10)FOREIGN,姓名C(20),工龄I)
C.CREATE TABLE教师表(职工号C(10)FOREIGN KEY,姓名C(20),工龄I)
D.CREATE TABLE教师表(职工号C(10)PRIMARY KEY,姓名C(20),工龄I)
第8题
利用SQL语句,检索仓库中至少有一名职工的仓库信息,正确的命令是
A.SELECT * FROM 仓库表 WHERE IN; (SELECT 仓库号 FROM 职工表)
B.SELECT * FROM 仓库表 WHERE NOT IN; (SELECT 仓库号 FROM 职工表)
C.SELECT * FROM 仓库表 WHERE 仓库号 EXISTS; (SELECT * FROM 职工表 WHERE 仓库号=仓库表.仓库号)
D.SELECT * FROM 仓库表 WHERE EXISTS; (SELECT * FROM 职工表 WHERE 仓库号=仓库表.仓库号)
第9题
A.SELECT姓名FROM职工
B.SELECT*FROM职工
C.SELECT姓名FROM职工 WHILE职工号=265
D.SELECT*FROM职工WHILE职工号=265
第10题
利用SQL语句,检索仓库中至少有一名职工的仓库信息,正确的命令是
A.SELECT*FROM仓库表WHERE IN; (SELECT仓库号FROM职工表)
B.SELECT*FROM仓库表WHERE NOT IN; (SELECT仓库号FROM职工表)
C.SELECT*FROM仓库表WHERE仓库号EXISTS; (SELECT*FROM职工表WHERE仓库号=仓库表.仓库号)
D.SELECT*FROM仓库表WHERE EXISTS; (SELECT*FROM职工表WHERE仓库号=仓库表.仓库号)
为了保护您的账号安全,请在“上学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!