public abstract class LYEntityDbContext
     
              where DB : DbContext, new()        where T : LYEntityDbContext
      
        {        public void GenerateHashCode() {            var thisTime = this.GetType().GetProperties().Select(p => p.GetValue(this).GetHashCode());            this.changes.Add(thisTime);        }        private List
       
        
         > changes = new List
         
          
           >(); private bool executed = true; private bool hasChanged { get { if (this.changes.Count < 2) { return false; } var result = !this.changes.First().Except(this.changes.Last()).Any(); return result; } } public bool Executed() { return this.executed; } public static IEnumerable
           
             Find(Action
            
              action, params object[] keyValues) { return Find(action, true, keyValues); } public static IEnumerable
             
               Find(Action
              
                action, bool inBatch, params object[] keyValues) { if (inBatch) { using (var db = new DB()) { var hasChanged = false; for (int i = 0; i < keyValues.Length; i++) { var id = keyValues[i]; var t = db.Set
               
                ().Find(id); yield return t; t.GenerateHashCode(); action(t); t.GenerateHashCode(); if (!hasChanged) { hasChanged = t.hasChanged; } } if (hasChanged) { db.SaveChanges(); } } } else { foreach (var id in keyValues) { yield return Find(action, id); } } } public static T Find(Action
                
                  action, object id) { using (var db = new DB()) { var t = db.Set
                 
                  ().Find(id); t.GenerateHashCode(); action(t); t.GenerateHashCode(); if (t.hasChanged) { try { db.SaveChanges(); t.executed = true; } catch (Exception) { t.executed = false; } } return t; } } public static IEnumerable
                  
                    FindAll
                   
(Func
                    
                      where, Func
                     
                       orderby, int skip, int take, out int all) { using (var db = new DB()) { if (where == null) { var r = db.Set
                      
                       (); all = r.Count(); return r; } all = db.Set
                       
                        ().Count(where); if (orderby == null) { var r = db.Set
                        
                         ().Where(where); return r; } if (take <= 0) { var r = db.Set
                         
                          ().Where(where).OrderBy(orderby); return r; } if (skip <= 0) { var r = db.Set
                          
                           ().Where(where).OrderBy(orderby).Take(take); return r; } var rr = db.Set
                           
                            ().Where(where).OrderBy(orderby).Skip(skip).Take(take); return rr; } } }