diff --git a/Models/CommonDbContext.cs b/Models/CommonDbContext.cs
index 1b36e3c..5c9780a 100644
--- a/Models/CommonDbContext.cs
+++ b/Models/CommonDbContext.cs
@@ -21,6 +21,8 @@ namespace NejCommon.Models;
         {
         }
 
+        public abstract CommonDbContext CreateCopy();
+
         public async Task<bool> ApiSaveChangesAsync()
         {
             try
@@ -78,19 +80,22 @@ namespace NejCommon.Models;
         {
             var entity = ChangeTracker.Entries<T>().Select(x => x.Entity).FirstOrDefault(predicate.Compile());
 
+            //find in change tracker
             if (entity != null && Entry(entity).State == EntityState.Deleted)
             {
                 Entry(entity).State = EntityState.Modified;
             }
 
+            //find in currentDb
             if (entity == null)
             {
                 entity = await Set<T>().FirstOrDefaultAsync(predicate);
             }
 
+            //find in up-to-date db
             if (entity == null)
             {
-                var newAppDB = Activator.CreateInstance(this.GetType()) as CommonDbContext;
+                var newAppDB = CreateCopy();
 
                 entity = await newAppDB.Set<T>().FirstOrDefaultAsync(predicate);
 
@@ -98,6 +103,8 @@ namespace NejCommon.Models;
                 if (entity != null && this.Entry(entity).State == EntityState.Detached)
                     Attach(entity);
             }
+
+            //create if not found
             if (entity == null)
             {
                 var newEntity = factory();
@@ -110,15 +117,30 @@ namespace NejCommon.Models;
         public T FindOrCreate<T>(Expression<Func<T, bool>> predicate, Func<T> factory) where T : class
         {
             var entity = ChangeTracker.Entries<T>().Where(e => e.State != EntityState.Deleted).Select(x => x.Entity).FirstOrDefault(predicate.Compile());
-            //var entity = this.;
+            
+            //find in change tracker
+            if (entity != null && Entry(entity).State == EntityState.Deleted)
+            {
+                Entry(entity).State = EntityState.Modified;
+            }
+            
+            //find in currentDb
             if (entity == null)
             {
-                var newAppDB = Activator.CreateInstance(this.GetType()) as CommonDbContext;
+                entity = Set<T>().FirstOrDefault(predicate);
+            }
+            
+            //find in up-to-date db
+            if (entity == null)
+            {
+                var newAppDB = CreateCopy();
 
                 entity = newAppDB.Set<T>().FirstOrDefault(predicate);
                 if (entity != null)
                     Attach(entity);
             }
+
+            //create if not found
             if (entity == null)
             {
                 var newEntity = factory();