Question

SQL 多表联查 两表中id相同 显示姓名和成绩

Student中有Stu_id int和Stu_Name
Subject中有Sub_Stu_S_id和Sub_Stu_C#
显示Subject中Sub_Stu_C#和Student中Stu_Name

Answer 1

select t1.Sub_Stu_C,Stu_Name from Student t1 left join Subject t2 on t2.Sub_Stu_S_id=t1.Stu_id

个人建议：以后如果建立数据库的话，每个表都建一个字段id,int型，自动增加，外键可以再建立一个字段，比如Subject 建立一个StudentID字段。

Answer 2

select 姓名,成绩 from A表 inner join B表 where A.Id=B.Id
select 姓名字段，成绩字段 form A表名 left join B表名 where A.Id=B.Id

Answer 3

用别名
select a1.*，a2.* from table1 a1，table2 a2 where a1.?=a2.?