DbSet doesn't have a Find method in EF7

Question

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 d         


        

Answer 1

So...the above find methods worked great, but if you don't have a column named "Id" in your model, the whole thing is going to fail on the following line. I'm not sure why the OP would have put a hardcoded value into this spot

  Expression.Property(parameter, "Id"),

Here's a revision that will fix it for those that name our Id columns appropriately. :)

var keyCompare = key.Properties[0].Name;

        // 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>)
            Expression.Lambda(
                Expression.Equal(
                    Expression.Property(parameter, keyCompare),
                    //Expression.Property(parameter, "Id"),
                    Expression.Constant(keyValues[0])),
                parameter));

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

This STILL very well could fail if you have more than one Key setup on the entity object and the key you're looking up by isn't the first, but it should be quite a bit btter this way.