在SQL数据库中连接两个表 [英] Join two tables in SQL database

问题描述

我在SQL数据库中创建了两个表'Student'和'Book'。 '学生'表包括'卷号（主键），名称'列和'书'表包含'书号（主键），书名，作者姓名'。我如何加入这两张桌子，以便知道哪些书籍发给哪个学生。实际上我会将学生卷号输入我的课程，然后检查发给该学生的书籍。

需要帮助..



谢谢..

I have two tables 'Student' and 'Book' created in a SQL databse. 'Student' table consists of 'Roll number(Primary Key), Name' columns and 'Book' table consists of 'Book number(Primary key), Book name, Author name'. How can I join the two tables such that I know which books are issued to which Student.. Actually I will make Student Roll number feed into my program and then check the books issued to that student..
Help required..

Thank You..

推荐答案

简单的答案是：

你需要一张第三张表StudentHasBorrowedBook有2个PKs colums卷号和书号。



如果你有2个打印件，这个问题可能会变得复杂得多相同的'Book'

The simple answer is :
you need a 3rd table StudentHasBorrowedBook with 2 PKs colums Roll number and Book number.

That said the question might become much more complicated if you have 2 prints of the same 'Book'

SELECT Student.Rollnumber，Book.Bookname，Student.Studentname

FROM Student

INNER JOIN Book

ON Student.Booknumber = Book.Booknumber;

SELECT Student.Rollnumber, Book.Bookname, Student.Studentname
FROM Student
INNER JOIN Book
ON Student.Booknumber=Book.Booknumber;

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