Question

我不应该有这个错误。这是代码

drop database if exists myDB;
CREATE DATABASE IF NOT EXISTS myDB;
USE myDB;

CREATE TABLE teacher(
tId int auto_increment primary key,
fname varchar(50),
lname varchar(50),
sId varchar(50)
);


CREATE TABLE student(
sId varchar(50) not null primary key,
fname varchar(50),
lname varchar(50)
);


ALTER TABLE teacher
    ADD foreign key (sId) references student(sId);

 insert into student values ('123', 'a', 'aa');
 insert into student values ('456', 'b', 'bb');
 insert into teacher (fname, lname, sId) values ('t', 'tt', '123');
 insert into teacher (fname, lname, sId) values ('x', 'xx', '456');



 create or replace view showTeachersAndStudents as
    select teacher.fname, teacher.lname, student.sId, student.fname, student.lname 
                from teacher join student on teacher.sId = student.sId;

错误：错误代码：1060。重复列名称＆＃39; fname＆＃39;

请你帮忙，非常感谢你。

Answer 1

您的观点尝试两次返回fname和lname。

在视图中添加别名：

create or replace view showTeachersAndStudents as
    select teacher.fname fname_teacher, 
           teacher.lname lnamet_teacher, 
           student.sId, 
           student.fname fname_student, 
           student.lname lname_student
    from teacher 
    join student on teacher.sId = student.sId;

重复列名MySQL

1 个答案: