每个人都评论SQL，但是在EntityFramework中发生了什么?我看了整篇文章，没人能解出EF。所以几天后，我找到了一个解决方案: 在EF Core的上下文中创建模型有这样一条指令:modelBuilder。实体<客户端>(实体=>{实体。属性(e => e.d id).ValueGeneratedNever();

这也会产生错误，解决方案:你必须通过ValueGeneratedOnAdd()改变它的工作!

我不确定“插入表”的用途是什么，但如果你只是想插入一些值，请尝试:

Insert Into [tablename] (OpDescription,FilterID)
values ('Hierachy Update',1);

我有同样的错误消息出现，但我认为这应该工作。只要是主键，ID就应该自动递增。

This occurs when you have a (Primary key) column that is not set to Is Identity to true in SQL and you don't pass explicit value thereof during insert. It will take the first row, then you wont be able to insert the second row, the error will pop up. This can be corrected by adding this line of code [DatabaseGenerated(DatabaseGeneratedOption.Identity)] in your PrimaryKey column and make sure its set to a data type int. If the column is the primary key and is set to IsIDentity to true in SQL there is no need for this line of code [DatabaseGenerated(DatabaseGeneratedOption.Identity)] this also occurs when u have a column that is not the primary key, in SQL that is set to Is Identity to true, and in your EF you did not add this line of code [DatabaseGenerated(DatabaseGeneratedOption.Identity)]

如果你在SQL服务器上得到这个错误，然后运行这个查询-

SET IDENTITY_INSERT tableName ON

这只适用于数据库的一个表 例:如果表名是student，那么查询如下:

SET IDENTITY_INSERT student ON

如果你在你的web应用程序或你使用实体框架得到这个错误，那么首先在SQL服务器上运行这个查询，并更新你的实体模型(。Edmx文件)并构建您的项目，此错误将被解决

你可以简单地使用这句话，例如，如果你的表名是学校。 在插入之前，确保identity_insert设置为ON，在插入查询之后，将identity_insert设置为OFF

SET IDENTITY_INSERT School ON
/*
  insert query
  enter code here
*/
SET IDENTITY_INSERT School OFF

我使用asp.net core 5.0，我得到这个错误。我得到这个错误，因为我添加了另一个数据并触发了另一个.SaveChanges()方法，如下所示:

 _unitOfWorkVval.RepositoryVariantValue.Create(variantValue);
 int request = HttpContext.Response.StatusCode;
 if (request == 200)
 {
     int tryCatch = _unitOfWorkCVar.Complete();
     if (tryCatch != 0)
     {
         productVariant.CategoryVariantID = variantValue.CategoryVariantID;
         productVariant.ProductID = variantValue.ProductID;
         productVariant.CreatedDate = DateTime.Now;
         _unitOfWorkProductVariant.RepositoryProductVariant.Create(productVariant);
         _unitOfWorkVval.RepositoryVariantValue.Create(variantValue);
         int request2 = HttpContext.Response.StatusCode;
         if(request==200)
         {
             int tryCatch2=_unitOfWorkProductVariant.Complete();//The point where i get that error
         }///.......