我已经开始考虑通用 EF 方法,并且我发现了该帖子http://blog.damianbrady.com.au/2012/03/07/a-generic-crud-repository-for-entity-framework/
代码片段:
protected Dictionary<string, object> CachedObjects = new Dictionary<string, object>();
protected ObjectSet<TEntity> GetObjectSet<TEntity>() where TEntity : EntityObject
{
var fulltypename = typeof(TEntity).AssemblyQualifiedName;
if (fulltypename == null)
throw new ArgumentException("Invalid Type passed to GetObjectSet!");
if (!CachedObjects.ContainsKey(fulltypename))
{
var objectset = base.CreateObjectSet<TEntity>();
CachedObjects.Add(fulltypename, objectset);
}
return CachedObjects[fulltypename] as ObjectSet<TEntity>;
}
...
public TEntity GetFirstOrDefault<TEntity>(Func<TEntity, bool> predicate) where TEntity : EntityObject
{
return GetObjectSet<TEntity>().FirstOrDefault(predicate);
}
现在,如果那两行代码相等?
adapter.db.GetFirstOrDefault<MyTable>(x => x.ID == 1);
adapter.db.MyTable.FirstOrDefault(x => x.ID == 1);
我在问,因为我不想将所有项目加载到内存中,然后对它们进行一些过滤。有什么方法可以使这样的通用操作像IQueryable<T>
?