Question

如何使用EF5删除实体？我收到此错误：

The object cannot be deleted because it was not found in the ObjectStateManager.

当我尝试呼叫时。删除我的DbSet。谷歌搜索后我尝试了

mycontext.Attach(entity)
mycontext.Remove(entity)

但是这样我得到了：

An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.

那么，它是否在ObjectStateManager中？！：）

我的实体是这样的：

[Table("Words")]
public class Word : IWord
{
    [Key, Required]
    public int WordId { get; set; }

    [Required, StringLength(50)]
    public string Tag { get; set; }

    //Foreign Key
    public int VocabularyId { get; set; }

    //Navigation
    public virtual Vocabulary Vocabulary { get; set; }
    public virtual Language Language { get; set; }
    public virtual List<Translation> Translations { get; set; }

}

Answer 1

您可以考虑2个方案：

<强> 1。已连接方案：您从数据库加载实体并将其标记为已删除

var word = ctx.Words.Where(a=>a.WordId == wordId).First();
ctx.DeleteObject(word);
ctx.SaveChanges();

<强> 2。已断开连接的方案：附加现有实体并将其标记为已删除

var word = new Word() { WordId = id };
ctx.Words.Attach(word);
ctx.DeleteObject(word);
ctx.SaveChanges();

第二种方法将帮助您避免不必要的数据库往返

EF5删除实体

1 个答案: