Include demands that the shape of the query doesn’t change. It means that your query must return IQueryable<Match>. GroupBy operator is probably considered as shape changing because it returns IQueryable<IGrouping<TKey, TSource>>. Once the shape of the query changes all Include statements are omitted. Because of that you cannot use Include with projections, custom joins and … Read more
In Entity Framework 6.1+ you can use this attribute on your model: [Index(IsUnique=true)] You can find it in this namespace: using System.ComponentModel.DataAnnotations.Schema; If your model field is a string, make sure it is not set to nvarchar(MAX) in SQL Server or you will see this error with Entity Framework Code First: Column ‘x’ in table … Read more
The difference is that in the first case the retrieved user is not tracked by the context so when you are going to save the user back to database you must attach it and set correctly state of the user so that EF knows that it should update existing user instead of inserting a new … Read more
You can have multiple contexts for single database. It can be useful for example if your database contains multiple database schemas and you want to handle each of them as separate self contained area. The problem is when you want to use code first to create your database – only single context in your application … Read more