需要有关MS SQL Solution的帮助 [英] Need help on MS SQL Solution

问题描述

我有三个表，例如SCHOOL，ORIENTATION和SUBJECTS。

表格具有以下属性

  CREATE   TABLE  [dbo]。[SCHOOL]（
 [ID_chool] [ int ]  IDENTITY （ 1 ， 1 ） NOT   NULL ，
 [SchoolName] [ nvarchar ]（ 50 ） NOT   NULL ，
 [AcademicYear] [ nvarchar ]（ 15 ） NOT   NULL ，
 [地址] [ nvarchar ]（ 50 ） NOT   NULL ，
 [ID_Person] [ int ] 不  NULL ，
 [ID_Municipality] [ int ]  NOT   NULL ，
  CONSTRAINT  [PK_SCHOOL]  PRIMARY   KEY   CLUSTERED  

  CREATE   TABLE  [dbo]。[ORIENTATION]（
 [ID_Orientation] [ int ]  IDENTITY （ 1 ， 1 ） NOT   NULL ， 
 [ID_School] [ int ]  NOT   NULL ，
 [OrientationName] [ nvarchar ]（ 50 ） NULL ，
  CONSTRAINT  [PK_ORIENTATION]  PRIMARY  < span class =code-keyword> KEY   CLUSTERED  

和第三个表

  CREATE   TABLE  [dbo]。[SUBJECT ]（
 [ID_Subject] [ int ]  IDENTITY （ 1 ， 1 ） NOT   NULL ，
 [SubjectName] [ nvarchar ]（ 50 ） NOT   NULL ，
 [ID_Orientation] [ int  ]  NOT   NULL ，
  CONSTRAINT  [PK_SUBJECT]  PRIMARY   KEY   CLUSTERED  

问题是小学没有ORIENTATIONS，所以他们不需要OrientationName，只有中学需要OrientationName 。

如何解决这个问题，以便我可以为小学注册科目。

P.S.我的项目有15个表，但我遇到了这个问题并且无法自己解决这个问题。

提前感谢您的回复。

干杯。

解决方案

这似乎不是孤立的问题。



为什么缺乏方向导致问题？唯一包含学校和方向的表是方向表 - 所以只是不要创建记录！

然后在Subject表的ID_Orientation字段中允许空值并且你是固定的，不是'你呢？



如果没有数据来确切地指出问题是什么，很难弄清楚为什么这会给你带来困难！ ：笑：

I have three tables like SCHOOL, ORIENTATION and SUBJECTS.
The tables have the following attributes

CREATE TABLE [dbo].[SCHOOL](
	[ID_chool] [int] IDENTITY(1,1) NOT NULL,
	[SchoolName] [nvarchar](50) NOT NULL,
	[AcademicYear] [nvarchar](15) NOT NULL,
	[Address] [nvarchar](50) NOT NULL,
	[ID_Person] [int] NOT NULL,
	[ID_Municipality] [int] NOT NULL,
 CONSTRAINT [PK_SCHOOL] PRIMARY KEY CLUSTERED 

CREATE TABLE [dbo].[ORIENTATION](
	[ID_Orientation] [int] IDENTITY(1,1) NOT NULL,
	[ID_School] [int] NOT NULL,
	[OrientationName] [nvarchar](50) NULL,
 CONSTRAINT [PK_ORIENTATION] PRIMARY KEY CLUSTERED

And the third table

CREATE TABLE [dbo].[SUBJECT](
	[ID_Subject] [int] IDENTITY(1,1) NOT NULL,
	[SubjectName] [nvarchar](50) NOT NULL,
	[ID_Orientation] [int] NOT NULL,
 CONSTRAINT [PK_SUBJECT] PRIMARY KEY CLUSTERED 

The problem is that the primary schools don't have ORIENTATIONS, so they don't need an OrientationName, only the secondary schools need an OrientationName.
How to solve this problem so I can register the subjects for primary schools.
P.S. My project has 15 tables, but I'm stuck in this problem and can't solve this problem by myself.
Thank you in advance for your reply.
Cheers.

解决方案

That doesn't seem to be a problem in isolation.

Why would the lack of "orientation" cause a problem? The only table which includes a school and an orientation is the orientation table - so just don't create a record!
Then allow nulls in the ID_Orientation field of the Subject table and you are fixed, aren't you?

Without data to indicate exactly what the problem is it's hard to work out why this is causing you difficulties! :laugh:

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