插入语句错误

Question

我有表dbo.Students_Old与列：

名称（varchar），DocNum（int），组（varchar），表格（varchar）。

它没有主键，我需要对该表进行规范化。 因此，我将制作三个表：

dbo.Students（StudentId（int主键），Name（varchar），Group（int fk），Form（int fk），

dbo.Forms（FormId（int pk），FName（varchar）），dbo.Groups（GroupId（int pk），GName（varchar））。

而且我还需dbo.Students_Old数据填充所有这些表。 我的代码是：

CREATE TABLE dbo.Groups(GroupId int IDENTITY(1,1) PRIMARY KEY, GName nvarchar(10));

GO

INSERT INTO dbo.Groups(GName) 
  select Group
  from dbo.Students_Old
  group by Group

GO

CREATE TABLE dbo.Forms(FormId int IDENTITY(1,1) PRIMARY KEY, Form nvarchar(20));

INSERT INTO dbo.Forms(Form) 
select Form
from dbo.Students_Old
group by Form

GO

CREATE TABLE dbo.Students (StudentId int PRIMARY KEY, Name nvarchar(50),
Form int NOT NULL,
Group int NOT NULL,
 CONSTRAINT Form FOREIGN KEY(StudentId) REFERENCES dbo.Forms(FormId),
 CONSTRAINT Grup FOREIGN KEY(StudentId) REFERENCES dbo.Groups(GroupId));

GO

INSERT INTO dbo.Students(StudentId, Name, Form, Group) 
select DocNum, Name, f.FormId, g.GroupId 
from dbo.Students_Old s
join dbo.Forms f on s.Form=f.Form
join dbo.Groups g on s.Group=g.GName

Students_Old.DocNum也是唯一的。

表创建常态，但是在插入语句上我有一个错误：

The INSERT statement conflicted with the FOREIGN KEY constraint "Form". The conflict occurred in database "DBNames", table "dbo.Forms", column 'FormId'.

请帮帮我。

Answer 1

不确定是否是这种情况，因为您收到FOREIGN KEY错误，但是请尽量避免使用诸如GROUP或其他保留字之类的列名。 虽然可以避免在表创建步骤中出错，但是在此类表的修改/更新过程中可能会遇到严重的问题。

Answer 2

在新数据库上执行以下查询

CREATE TABLE dbo.Groups(GroupId int IDENTITY(1,1) PRIMARY KEY, GName nvarchar(10));

GO

INSERT INTO dbo.Groups(GName) 
  select Group
  from dbo.Students_Old
  group by Group

GO

CREATE TABLE dbo.Forms(FormId int IDENTITY(1,1) PRIMARY KEY, Form nvarchar(20));

INSERT INTO dbo.Forms(Form) 
select Form
from dbo.Students_Old
group by Form

GO

CREATE TABLE dbo.Students (StudentId int PRIMARY KEY, Name nvarchar(50),
Form int NOT NULL,
[Group] int NOT NULL,
 CONSTRAINT Form FOREIGN KEY(Form) REFERENCES dbo.Forms(FormId),
 CONSTRAINT Grup FOREIGN KEY(Group) REFERENCES dbo.Groups(GroupId));

GO

INSERT INTO dbo.Students(StudentId, Name, Form, Group) 
select DocNum, Name, f.FormId, g.GroupId 
from dbo.Students_Old s
join dbo.Forms f on s.Form=f.Form
join dbo.Groups g on s.Group=g.GName

我已更改为以下几行

 CONSTRAINT Form FOREIGN KEY(Form) REFERENCES dbo.Forms(FormId),
 CONSTRAINT Grup FOREIGN KEY([Group]) REFERENCES dbo.Groups(GroupId));

在您的代码中，外键在StudentID列上

Answer 3

执行以下查询。

CREATE TABLE dbo.Groups(GroupId int IDENTITY(1,1) PRIMARY KEY, GName nvarchar(10));

GO

INSERT INTO dbo.Groups(GName) 
  select [Group]
  from dbo.Students_Old
  group by [Group]

GO

CREATE TABLE dbo.Forms(FormId int IDENTITY(1,1) PRIMARY KEY, Form nvarchar(20));

INSERT INTO dbo.Forms(Form) 
select Form
from dbo.Students_Old
group by Form

GO

CREATE TABLE dbo.Students (StudentId int PRIMARY KEY, Name nvarchar(50),
Form int NOT NULL,
[Group] int NOT NULL,
 CONSTRAINT Form FOREIGN KEY(StudentId) REFERENCES dbo.Forms(FormId),
 CONSTRAINT Grup FOREIGN KEY(StudentId) REFERENCES dbo.Groups(GroupId));

GO

INSERT INTO dbo.Students(StudentId, Name, Form, [Group]) 
select DocNum, Name, f.FormId, g.GroupId 
from dbo.Students_Old s
join dbo.Forms f on s.Form=f.Form
join dbo.Groups g on s.[Group]=g.GName