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单选题 为ReaderType表中的Typename添加唯一约束,正确的语句是
学科：数据库原理及应用
时间：2023-11-17 20:47:26
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题目1单选题
插入语句命令是A. INSERT INTOB. UPDATEC. DELETED. SELECT
题目2单选题
更新数据命令A. INSERT INTOB. UPDATEC. DELETED. SELECT
题目3单选题
删除数据命令A. INSERT INTOB. UPDATEC. DELETED. SELECT
题目4单选题
向表ReaderType中插入数据,正确的是A. INSERT INTO ReaderType VALUES(1,"企业职工",5,30)B. INSERT INTO ReaderType VALUES(1;"企业职工";5;30)C. INSERT INTO ReaderType VALUE(1,"企业职工",5,30)D. INSERT INTO ReaderType VALUE(1;"企业职工";5;30)
题目5单选题
更改ReaderType中的数据,将"企业职工"的借阅天数改为40天,正确的语句是A. UPDATE TABLE ReaderType SET LimitDays=40 WHERE Typename='企业职工'B. UPDATE ReaderType SET LimitDays=40C. UPDATE ReaderType SET LimitDays=40 WHERE Typename='企业职工'D. UPDATE TABLE ReaderType SET LimitDays=40
题目6单选题
删除ReaderType表中"企业职工"的信息,正确的语句是A. DELETE ReaderTypeB. DELETE ReaderType WHERE Typename='企业职工'C. DELETE TABLE ReaderType WHERE Typename='企业职工'D. DELETE TABLE ReaderType
题目7单选题
删除ReaderType表中所有数据,正确的命令是A. DELETE TABLE ReaderTypeB. DELETE ReaderTypeC. DROP TABLE ReaderTypeD. DROP ReaderType
题目8单选题
将表ReaderType中的TypeID设置为主键,正确的命令是A. ALTER TABLE ReaderType ADD CONSTRAINT primary key (TypeID)B. ALTER TABLE ReaderType ADD CONSTRAINT PK_ReaderType(TypeID)C. ALTER TABLE ReaderType ADD PK_ReaderType primary key (TypeID)D. ALTER TABLE ReaderType ADD CONSTRAINT PK_ReaderType primary key (TypeID)
题目9单选题
为ReaderType表中的Typename添加唯一约束,正确的语句是A. ALTER TABLE ReaderType ADD CONSTRAINT UQ_ReaderType unique (Typename)B. ALTER TABLE ReaderType ADD CONSTRAINT unique (Typename)C. ALTER TABLE ReaderType ADD CONSTRAINT UQ_ReaderType (Typename)D. ALTER TABLE ReaderType ADD UQ_ReaderType unique (Typename)
题目10单选题
为表Reader中的Email字段添加检查约束,要求该字段需要有"@"符号,正确的命令是A. ALTER TABLE Reader ADD CONSTRAINT check (Email like '%@%')B. ALTER TABLE Reader ADD CONSTRAINT CK_Reader (Email like '%@%')C. ALTER TABLE Reader ADD CONSTRAINT CK_Reader check (Email like '%@%')D. ALTER TABLE Reader ADD CK_Reader check (Email like '%@%')
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