无法将值NULL插入列"ID" [英] Cannot insert the value NULL into column 'ID'

问题描述

当使用Linq to Sql时，出现异常无法将值NULL插入列'ID'中"，我将ID属性留为空白，但是我将ID设置为在DBML文件中自动生成.当我插入没有ID的代码并且不使用linq来让sql自动为我自动生成时，此方法会正常工作.问题是LINQ抛出异常是因为它看到ID为空，即使LINQ只是允许它通过SQL也可以.

I am getting the exception "Cannot insert the value NULL into column 'ID'" when using Linq to Sql , I am leaving the ID property blank , but I have set my ID to auto-generate in my DBML file. This will work fine when I insert without an ID and let sql auto generate for me not using linq. The problem is LINQ is throwing an exception because it sees that ID is empty , even though if LINQ would just let it go through SQL is ok with it.

    [global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_ID", AutoSync=AutoSync.OnInsert, DbType="Int NOT NULL", IsPrimaryKey=true, IsDbGenerated=true)]
    public int ID
    {
        get
        {
            return this._ID;
        }
        set
        {
            if ((this._ID != value))
            {
                this.OnIDChanging(value);
                this.SendPropertyChanging();
                this._ID = value;
                this.SendPropertyChanged("ID");
                this.OnIDChanged();
            }
        }
    }

推荐答案

您需要在列定义中包括"IDENTITY":

You need to include 'IDENTITY' in your column definition:

[global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_ID", AutoSync=AutoSync.OnInsert, DbType="Int NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)]
public int ID
{ ... }

如果无法解决，请尝试同时添加UpdateCheck=UpdateCheck.Never.

If that wont fix it try adding UpdateCheck=UpdateCheck.Never as well.

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