CODEWITHSUNDEEP
sqlasp.net-mvcentity-frameworkef-code-firsttable-per-hierarchy
GisMofx
GisMofx

Reputation: 1024

EF : MVC : ASP: TPH Error - Store update, insert, or delete ... number of rows (0). Entities ... modified or deleted ... Refresh ObjectStateManager

Error Message: "Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries."

Hello All,

I've created a Code First TPH(Table Per Hierarchy) within MVC and EF with a SQL compact db.

Here's the Class diagram/Hierarchy:

Class Diagram

Client and SalesRep both inherit the BaseUser class. The Key is "UserID" and it's coded with the Data Annotation [Key](I'm aware that 'ID' should set it as well)

Here's where I'm at: I can seed the database with a few entries. When I try to set the "UserID" in the seeding method it seems to ignore it and just apply the UserID in numerical order...(Seems ok to me?)

furthermore here's my DbContext

public class SiteDB:DbContext
{
    public DbSet<BaseUser> AllUsers { get; set; }//enable TPH
    public DbSet<SalesRep> SalesReps { get; set; }
    public DbSet<Client> Clients { get; set; }
}

Next,

I have created a controller for Clients -> ClientsController with strongly typed Razor Views. With this. I now have a CRUD for the Clients. I can create new Clients without any issue, but when I try to edit a Client entry, I get the error message stated above.

I did notice something interesting I stepped through the code and the error is happening on the db.SaveChanges();

When the client is passed back into the ActionResult Edit method the UserID=0! Bizarre? I'm not sure if this is a bug or if it's an actual issue that's causing this.

UserID=0

Your help with this is appreciated. Thanks!

Upvotes: 1

Views: 821

Answers (1)

Massimo Zerbini
Massimo Zerbini

Reputation: 3191

To modify an entity you need to get it from the database: when you pass back the modified values in the Edit action you need to retrive the entity from the db object, getting it by ID, apply the modified values and save it.

Here an example:

public ActionResult Edit(int id, MyModel model){
 using (SiteDBdb = new SiteDB()){
  Client cl = (from c in db.Clients where c.id == id select c).First();
  cl.MyProp = model.MyProp;
  ...
  db.SaveChanges();
 }
 ...
}

Upvotes: 0

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