The name Savechanges() does not exist in the current context

Naruto Reddy

6y3.2kLearn iOS Programming

Hello Experts,

I am migrating my code from EF to EF Core.

We do have an Igenericreposirory.

And this Igenericreposirory is inheriting by Genericreposirory.

IGenericreposirory

using System;

using System.Collections.Generic;

using System.Linq;

using System.Linq.Expressions;

using System.Threading.Tasks;

namespace DataLayer.Repositories.Base

{

public interface IGenericRepository where T : class

{

T Add(T entity);

}

GenericRepository:

public class GeneralRepository : IGenericRepository

where T : class, IEntity, new()

{

protected readonly DbContext DbContext;

internal DbSet DbSet;

public GeneralRepository(DbContext dbContext)

{

if (dbContext == null)

throw new ArgumentNullException("dbContext");

this.DbContext = dbContext;

this.DbSet = this.DbContext.Set();

}

public virtual T Add(T entity)

{

#region Argument Validation

if (entity == null)

{

throw new ArgumentNullException("entity");

}

#endregion

var obj = DbSet.Add(entity);

SaveChanges();

return obj;

}

Here I am getting 2 errors while working with EF core

1 at return obj as "Cannot convert from 'Microsoft.EntityFrameworkCore.ChangeTracking.EntityEntry' to 'T'"

2 at Savechange() as "the name savechanges()" does not exists in the current context.

As far as i know , EF core supports all methods to fetch , Insert, ADD

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Laxmidhar Sahoo6y ago
Accepted answer
1- The add method does not return anything .So why you return T ,the generic type
public virtual void add(T entity)
{
DbSet.Add(entity);
}
// SaveChanges() is a method of DbContext class
//So you should call from the object like bellow that you assign in constructor
2- this.DbContext.SaveChanges();
Naruto Reddy6y ago
HI Laxminser,

I have figured it out.

But I have stuck at one more doubt. Can you please clear my confusion over here.
public virtual void AddOrUpdate(T entity)
{
#region Argument Validation if (entity == null)
{
throw new ArgumentNullException("entity");
}
#endregion
DbSet.AddOrUpdate(e => e.Id, entity); SaveChanges();
}
see the error as "DbSet does not contain a definition for AddorUpdate". I saw a blog where we can use "DbSet.Update" instead of AddorUpdate and some people saying it will come in the future versions. Is the statement a valid one?

Can you provide the solution for the above?

Thanks in advance.