如何在适用于 EFCore 的 Hotchocolate 中打开和关闭包含

Question

So I'm trying to figure out how to tell EfCore when to apply an include to an IQueryable object based on whether the GraphQl request from the client actually includes the related object.

Example:

• 2 Classes: Person, Payment

• Theses are kept in 2 different tables and related Person -> Payment in a one to many relationship

• I have 1 GraphQl Query set up to retrieve all people in the Database:

   [UseFiltering] [UseDbContext(typeof(DbAccess))] public IQueryable<Person> GetPeople([ScopedService] DbAccess db) { return db.People; }

• This returns just the fields in the People table ex: query: {people{sso,payments{amount, recipient{compayName}}}} response: { "data": { "people": [ { "sso": "000-00-0003", "payments": null } ] } }

• In order to get the payments my GetPeople func needs to be changed to

   [UseFiltering] [UseDbContext(typeof(DbAccess))] public IQueryable<Person> GetPeople([ScopedService] DbAccess db) { return db.People.Include(p => p.Payments); }

• This works but places an unneeded strain when the payments aren't part of the request (as the Include will run every time).

What I would like to do would be something like:

    var baseQuery = db.People;
        if (graphqlRequestIncludePayments)
        {
            baseQuery.Include(p => p.Payments);
        }
    return baseQuery;

But I cannot figure out how to check the GraphQl query to see if payments is requested. I know GraphQl will remove the excess data before returning to the consumer but that can be a lot of wasted bandwidth and memory on the server side.

I feel like there is a way to do this in the Hotchocolate ObjectType.Configure function but I cant see how.

Any help would be much appreciated, thanks:)

Answer 1

Tobias Tengler was correct this should be done through Projections