如何为行创建表并在它们之间建立链接？ [英] How to create a table for a row and link between them?

问题描述

我有一个表，其中商店名称，用户的问题，我希望存储多个用户的多个答案的问题。





用户名

`````````

名称问题

----------- --------

alice为什么要使用java？

thomes c和c ++有什么区别？



i想要这样





名称问题答案

-------- ---------------------------------------------

alice为什么要用java？ answer1，answer2，answer3



我的尝试：



i want存储使这个网站像这个问题有多个答案。

解决方案

简单：你需要多个表格。

第一个表存储用户：

 ID int，identity 
 UserName NVARCHAR 

第二个存储问题：

 ID int，identity 
问题NVARCHAR 
 AIDCorrect int，Answers.ID的外键
 AIDError1 int，Answers.ID的外键
 AIDError1 int ，Answers.ID的外键

然后答案：

 ID int，identity 
答案NAVRCHAR 

然后链接表：

 ID int，identity 
 QID int，外键到Questions.ID 
 UID int，Users.ID的外键
 GivenAnswer int，Answers.ID的外键，Nullable 

然后您可以使用SQL JOIN来检索所需的信息。

在您的示例中，您声明您想要的将多个答案从一个人存储到一行。那是不可取的。相反，你应该使用一个关联表。



所以设计应该像

 user 
 ---- 
  -  userid 
  -  name 
 
 question 
 -------- 
  -  questionid 
  -  questiontext 
 
回答
 ------ 
  - 用户ID 
  -  questionid 
  - 回答

欲了解更多信息，请查看关联实体 - 维基百科，免费的百科全书 [ ^ ]

i have a table in which store name,question of users and i want store multiple answers from multiple user for a question.


username
``````````
name question
-------------------
alice why use java?
thomes what is difference between c and c++?

i want like this


name question answer
-----------------------------------------------------
alice why use java? answer1,answer2,answer3

What I have tried:

i want to store make a page like this site where for a question have multiple answers.

解决方案

Simple: you need multiple tables.
The first table stores users:

ID          int, identity
UserName    NVARCHAR

The second stores questions:

ID          int, identity
Question    NVARCHAR
AIDCorrect  int, foreign key to Answers.ID
AIDError1   int, foreign key to Answers.ID
AIDError1   int, foreign key to Answers.ID

Then answers:

ID          int, identity
Answer      NAVRCHAR

Then the linking tables:

ID          int, identity
QID         int, foreign key to Questions.ID
UID         int, foreign key to Users.ID
GivenAnswer int, foreign key to Answers.ID, Nullable

You can then use SQL JOIN to retrieve the info you need.

In your example you state that you would like to store multiple answers from a person to a single row. That's not advisable. Instead you should use an associative table.

So the design shold be something like

user
----
- userid
- name

question
--------
- questionid
- questiontext

answer
------
- userid
- questionid
- answer

For more information, have a look at Associative entity - Wikipedia, the free encyclopedia[^]

这篇关于如何为行创建表并在它们之间建立链接？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！