如何改变相关联的字段的值 [英] How to change the value of associated field

问题描述

我有2个教学班，即它们之间的关联LINQ。

I have 2 classes with a LINQ association between them i.e.:

Table1:       Table2:
ID            ID
Name          Description
              ForiegnID

这里的关联 Table1.ID之间 - > Table2.ForiegnID

我需要能够改变Table2.ForiegnID的价值，但我不能，并认为这是因为联想的（当我删除它，它的工作原理）。

I need to be able to change the value of Table2.ForiegnID, however I can't and think it is because of the association (as when I remove it, it works).

因此​​，没有人知道我可以更改相关领域Table2.ForiegnID的价值？

Therefore, does anyone know how I can change the value of the associated field Table2.ForiegnID?

推荐答案

退房designer.cs文件。这是关键的属性。

Check out the designer.cs file. This is the key's property

[Column(Storage="_ParentKey", DbType="Int")]
public System.Nullable<int> ParentKey
{
    get
    {
        return this._ParentKey;
    }
    set
    {
        if ((this._ParentKey != value))
        {
            //This code is added by the association
            if (this._Parent.HasLoadedOrAssignedValue)
            {
                throw new System.Data.Linq.ForeignKeyReferenceAlreadyHasValueException();
            }
            //This code is present regardless of association
            this.OnParentKeyChanging(value);
            this.SendPropertyChanging();
            this._ParentKey = value;
            this.SendPropertyChanged("ParentKey");
            this.OnServiceAddrIDChanged();
        }
    }
}

这是协会属性。

[Association(Name="Parent_Child", Storage="_Parent", ThisKey="ParentKey", IsForeignKey=true, DeleteRule="CASCADE")]
public Parent Parent
{
    get
    {
        return this._Parent.Entity;
    }
    set
    {
        Parent previousValue = this._Parent.Entity;
        if (((previousValue != value) 
                    || (this._Parent.HasLoadedOrAssignedValue == false)))
        {
            this.SendPropertyChanging();
            if ((previousValue != null))
            {
                this._Parent.Entity = null;
                previousValue.Exemptions.Remove(this);
            }
            this._Parent.Entity = value;
            if ((value != null))
            {
                value.Exemptions.Add(this);
                this._ParentKey = value.ParentKey;
            }
            else
            {
                this._ParentKey = default(Nullable<int>);
            }
            this.SendPropertyChanged("Parent");
        }
    }
}

这是最好的分配通过协会，而不是关键的变化。这样，你就不必担心父母是否已加载。

It's best to assign changes through the association instead of the key. That way, you don't have to worry about whether the parent is loaded.

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