A-A+

若给出关系Student(S_no Shame Sage S_sex SD_name S_a

2022-08-05 20:36:30 问答库 阅读 171 次

问题详情

若给出关系Student(S_no,Shame,Sage,S_sex,SD_name,S_add,S_tel),并用SQL语言定义Student关系如下:CREATE Student(S_no CHAR(6), Sname CHAR(30)NOT NULL, Sage CHAR(30), S_sex CHAR(1), SD_name CHAR(20), S_add CHAR(30), S_tel CHAR(20), PRIMARY KEY(S_no));采用(41)向Student中插入记录能被正确地执行。
A.INSERT INTO Smdent(S_no,Sname,Sage,S_sex,SD_name,S_add,S_tel)VALUES("010456","黎敏","18",",",",")
B.INSERT INTO Student(S_no,Sname,Sage,S_sex,S_r)name,S_add,S_tel)VALUES("010456","黎敏","18","男","计算机学院","北京","88661200")
C.INSERT INTO Student(S_no,Sname,Sage,S_sex,SD_name,S_add,S_tel)VALUES(,"黎敏","18","F","计算机学院","北京","88661200")
D.INSERT INTO Student(S_no,Sname,Sage,S_sex,SD_name,S_add,S_tel)VALUES("010456",,"18","F","计算机学院","北京","88661200")

参考答案

正确答案:A
解析:本题考查SQL语言方面的基本知识。试题(41)的答案为A。选项B是错误的,因为定义Student关系时S_sex为一个字符,而选项B中插入S_sex处的数据为”男”占两个字符:选项C是错误的,因为定义 Student关系时S_no是主键,主键是不能取空值的,而选项C中插入S_no处的数据为空;选项D是错误的,因为定义Student关系时要求Sname不为空,而选项D中插入 Sname处的数据为空。

考点:关系