IDENTITY_INSERT设置为OFF [英] IDENTITY_INSERT is set to OFF

问题描述

大家好，



我只想刷新我对EF和LinQ的了解，这就是为什么我创建了一个具有CRUD功能的应用程序。现在的问题是我收到错误

当IDENTITY_INSERT设置为OFF时，无法在表'Book'中为标识列插入显式值。执行Add函数时。我知道我的代码是是的，因为我在以前的练习中总是使用这段代码。



这是我的btnAdd按钮中的代码：

  private   void  CreateBook（）
 {
  var  book =  new  Book（）; 
  var  addBook =  new  BookBusinessLayer（）; 
 book.Author = txtAuthor.Text; 
 book.Price =  decimal  .Parse（txtPrice.Text）; 
 book.Title = txtTitle.Text; 
 book.Year = txtYear.Text; 
 book.publisherId =  int  .Parse（dlistPublisher.SelectedValue）;  //  这是外键 
 addBook.AddBook（book）; 
} 
 

当我看到内部异常时，Book.Id = 0的值

但我没有设置Book.Id的值，因为它是我的主键



我应该如何摆脱这个错误



任何评论和答案将不胜感激：）

解决方案

在数据库级别打开表格上的身份。

SET IDENTITY_INSERT Book ON

使用此查询

  SET   IDENTITY_INSERT  Table_Name  ON  
 
  INSERT   INTO  Table_Name（ID， name）
  VALUES （ 5 ，'  David'）
 
  SET   IDENTITY_INSERT  Table_Name  OFF  

SET BOOK表的以下属性数据库中的Id列



身份规范是



（身份）是



身份增量1



身份种子1

Hi guys,

I just want to refresh my knowledge about EF and LinQ thats why I created an app that has the CRUD functionality.Now the problem is that I got the error
"Cannot insert explicit value for identity column in table 'Book' when IDENTITY_INSERT is set to OFF." when executing Add function.I know my code is correct because I always use this code in my previous exercises.

Here is the code in my btnAdd button:

private void CreateBook()
       {
           var book = new Book();
           var addBook = new BookBusinessLayer();
           book.Author = txtAuthor.Text;
           book.Price = decimal.Parse(txtPrice.Text);
           book.Title = txtTitle.Text;
           book.Year = txtYear.Text;
           book.publisherId = int.Parse(dlistPublisher.SelectedValue);//this is Foreign Key
           addBook.AddBook(book);
       }

And when I see the inner exception the value of Book.Id=0
but I didnt set the value of the Book.Id because it is my Primary Key

How should I get rid of this Error

Any comments and Answers will be appreciated :)

解决方案

Turn on identity on the table at the database level.
SET IDENTITY_INSERT Book ON

use this Query

SET IDENTITY_INSERT Table_Name ON

INSERT INTO Table_Name (ID, name)
VALUES (5, 'David')

SET IDENTITY_INSERT Table_Name OFF

SET Following properties for BOOK’s table Id Column in database

Identity Specification  Yes

(Is Identity)Yes

Identity Increment 1

Identity Seed  1

这篇关于IDENTITY_INSERT设置为OFF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！