DbSet doesn't have a Find method in EF7

I am trying to create a generic repository to access my database. In EF6 I was able to do that in order to get a specific entity:

protected IDbSet<T> dbset;

public T Get(object id)
{
    return this.dbset.Find(id);
}

DbSet in EF7 is missing a Find method. Is there a way to implement the above piece of code?

Here's a very crude, incomplete, and untested implementation of .Find() as an extension method. If nothing else, it should get you pointed in the right direction.

The real implementation is tracked by #797.

static TEntity Find<TEntity>(this DbSet<TEntity> set, params object[] keyValues)
    where TEntity : class
{
    var context = ((IAccessor<IServiceProvider>)set).Service.GetService<DbContext>();

    var entityType = context.Model.GetEntityType(typeof(TEntity));
    var key = entityType.GetPrimaryKey();

    var entries = context.ChangeTracker.Entries<TEntity>();

    var i = 0;
    foreach (var property in key.Properties)
    {
        var keyValue = keyValues[i];
        entries = entries.Where(e => e.Property(property.Name).CurrentValue == keyValue);
        i++;
    }

    var entry = entries.FirstOrDefault();
    if (entry != null)
    {
        // Return the local object if it exists.
        return entry.Entity;
    }

    // TODO: Build the real LINQ Expression
    // set.Where(x => x.Id == keyValues[0]);
    var parameter = Expression.Parameter(typeof(TEntity), "x");
    var query = set.Where((Expression<Func<TEntity, bool>>)
        Expression.Lambda(
            Expression.Equal(
                Expression.Property(parameter, "Id"),
                Expression.Constant(keyValues[0])),
            parameter));

    // Look in the database
    return query.FirstOrDefault();
}

In case you are using EF 7.0.0-rc1-final, below you find a small update for the code presented by @bricelam in the previous answer. By the way, thank you very much @bricelam - your code was extremely useful for me.

Here are my dependencies under "project.config":

"dependencies": {
    "EntityFramework.Commands": "7.0.0-rc1-final",
    "EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final",
    "Microsoft.Framework.Configuration.Json": "1.0.0-beta8",
    "Microsoft.Framework.ConfigurationModel": "1.0.0-beta4",
    "Microsoft.Framework.ConfigurationModel.Json": "1.0.0-beta4",
    "Microsoft.Framework.DependencyInjection": "1.0.0-beta8"
}

And below is the extension method for DbSet.Find(TEntity):

using Microsoft.Data.Entity;
using Microsoft.Data.Entity.Infrastructure;
using System;
using System.Linq;
using System.Linq.Expressions;

namespace Microsoft.Data.Entity.Extensions
{
    public static class Extensions
    {
        public static TEntity Find<TEntity>(this DbSet<TEntity> set, params object[] keyValues) where TEntity : class
        {
            var context = ((IInfrastructure<IServiceProvider>)set).GetService<DbContext>();

            var entityType = context.Model.FindEntityType(typeof(TEntity));
            var key = entityType.FindPrimaryKey();

            var entries = context.ChangeTracker.Entries<TEntity>();

            var i = 0;
            foreach (var property in key.Properties)
            {
                entries = entries.Where(e => e.Property(property.Name).CurrentValue == keyValues[i]);
                i++;
            }

            var entry = entries.FirstOrDefault();
            if (entry != null)
            {
                // Return the local object if it exists.
                return entry.Entity;
            }

            // TODO: Build the real LINQ Expression
            // set.Where(x => x.Id == keyValues[0]);
            var parameter = Expression.Parameter(typeof(TEntity), "x");
            var query = set.Where((Expression<Func<TEntity, bool>>)
                Expression.Lambda(
                    Expression.Equal(
                        Expression.Property(parameter, "Id"),
                        Expression.Constant(keyValues[0])),
                    parameter));

            // Look in the database
            return query.FirstOrDefault();
        }
    }
}

Can't comment because of reputation, but if you use RC2 (or later?) you should use

var context = set.GetService<ICurrentDbContext>().Context;

instead of

var context = set.GetService<DbContext>();

I've taken some of the previously provided answers and tweaked them to fix a couple of problems:

• Implicitly captured closure

• Key shouldn't be hard coded to "Id"

  public static TEntity Find<TEntity>(this DbSet<TEntity> set, params object[] keyValues) where TEntity : class
  {
      var context = set.GetService<DbContext>();
  
      var entityType = context.Model.FindEntityType(typeof(TEntity));
      var key = entityType.FindPrimaryKey();
  
      var entries = context.ChangeTracker.Entries<TEntity>();
  
      var i = 0;
      foreach (var property in key.Properties)
      {
          var i1 = i;
          entries = entries.Where(e => e.Property(property.Name).CurrentValue == keyValues[i1]);
          i++;
      }
  
      var entry = entries.FirstOrDefault();
      if (entry != null)
      {
          // Return the local object if it exists.
          return entry.Entity;
      }
  
      var parameter = Expression.Parameter(typeof(TEntity), "x");
      var query = set.AsQueryable();
      i = 0;
      foreach (var property in key.Properties)
      {
          var i1 = i;
          query = query.Where((Expression<Func<TEntity, bool>>)
           Expression.Lambda(
               Expression.Equal(
                   Expression.Property(parameter, property.Name),
                   Expression.Constant(keyValues[i1])),
               parameter));
          i++;
      }
  
      // Look in the database
      return query.FirstOrDefault();
  }
  

Find finally arrives into Entity Framework core.