如何在 EntityKey 上编写通用主键查找器？

发布于 2024-10-07 19:06:04 字数 961 浏览 2 评论 0原文

我认为下面的代码非常有用。但我尝试创建 EntityKEY。我用过：

 EntityKey key = new EntityKey(entitySetKEYName, "XTableId", id);

But i dont want to use this. my table PRIMARYID YtableId,ZTableId, etc... How can i write this: EntityKey key = new EntityKey(entitySetKEYName, Find().PrimaryKEY, id);

       public T GetByPrimaryKey<T>(int id)
        {
            string entitySetName = _context.MetadataWorkspace.GetEntityContainer(_context.DefaultContainerName, DataSpace.CSpace).BaseEntitySets.
                Where(q => q.ElementType.Name == typeof(T).Name).FirstOrDefault().Name;
            string entitySetKEYName = string.Format("{0}.{1}", _context.DefaultContainerName, entitySetName);
            EntityKey key = new EntityKey(entitySetKEYName, "XTableId", id);

            return (T)_context.GetObjectByKey(key);
        }

如何自动检测主键？？？？？？？？？？？？？？？

原文

i think that below codes is very useful. But i try to create EntityKEy. i used:

 EntityKey key = new EntityKey(entitySetKEYName, "XTableId", id);

But i dont want to use this. my table PRIMARYID YtableId,ZTableId, etc... How can i write this:

 EntityKey key = new EntityKey(entitySetKEYName, Find().PrimaryKEY, id);

       public T GetByPrimaryKey<T>(int id)
        {
            string entitySetName = _context.MetadataWorkspace.GetEntityContainer(_context.DefaultContainerName, DataSpace.CSpace).BaseEntitySets.
                Where(q => q.ElementType.Name == typeof(T).Name).FirstOrDefault().Name;
            string entitySetKEYName = string.Format("{0}.{1}", _context.DefaultContainerName, entitySetName);
            EntityKey key = new EntityKey(entitySetKEYName, "XTableId", id);

            return (T)_context.GetObjectByKey(key);
        }

HOW CAN AUTOMATICALLY DETECT PRIMARY KEY????????????????

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

可可 2024-10-14 19:06:04

首先，PK不一定是Int32，它可以是Guid甚至多属性复杂键，所以泛型方法应该除了Object之外作为PK...
这是我的相当丑陋的变体，但它完成了工作，尽管它需要适当的测试。

    static void Main(string[] args)
    {
        var entity = GetEntityByKey<Entity>(Guid.Empty);
    }
    private static T GetEntityByKey<T>(object key) where T : class 
    {
        using (var context = new ObjectContext("Name=ModelContainer"))
        {
            var set = context.CreateObjectSet<T>().EntitySet;
            var pk = set.ElementType.KeyMembers[0]; // careful here maybe count can be o or more then 0
            EntityKey entityKey = new EntityKey(set.EntityContainer.Name+"."+set.Name, pk.Name, key);
            return (T)context.GetObjectByKey(entityKey);
        }
    }

First,PK is not necessary Int32, it can be Guid or even multi property complex key, so generic method should except Object as PK...
Here is my pretty ugly variant, but it does the job, though it need proper testing.

    static void Main(string[] args)
    {
        var entity = GetEntityByKey<Entity>(Guid.Empty);
    }
    private static T GetEntityByKey<T>(object key) where T : class 
    {
        using (var context = new ObjectContext("Name=ModelContainer"))
        {
            var set = context.CreateObjectSet<T>().EntitySet;
            var pk = set.ElementType.KeyMembers[0]; // careful here maybe count can be o or more then 0
            EntityKey entityKey = new EntityKey(set.EntityContainer.Name+"."+set.Name, pk.Name, key);
            return (T)context.GetObjectByKey(entityKey);
        }
    }

回复收藏 0 原文

~没有更多了~