Lambda expression for multiple Include

[ovation22]

Hi Steve,

I appreciate all the work on this that you (and community) have put into this.

Is it possible to have multiple includes using expression syntax? I was able to chain includes using string then expression, but would really like to use the typed expressions if possible.

Expected behavior:

Query.Include(x => x.foo).Include(x => x.bar)

should compile and produce the same results as:

Query.Include("foo").Include(x => x.bar)

I'm happy to look into what it would take and will try to spend some time with it this weekend.

[fiseni]

Hi @ovation22,

Sure, you can do that. Just start with Query once again. In case of Include and Order functionalities, once you enter the second level, you can use only "Then" definitions, so you have to start over with Query.

Query.Include(x => x.foo);
Query.Include(x => x.bar);

It doesn't matter in which order you define the statements, or if you use chaining, or if you writing everything in separate statements. Whatever you add through the builder (named as Query), will be evaluated in predefined order.

Examples:

Query.Where(x => x.Name == "Something")
     .Paginate(10, 20)
     .Include(x => x.SomeProperty1)
         .ThenInclude(x => x.SecondLevelProperty1)
         .ThenInclude(x => x.ThirdLevelProperty1);
Query.Include(x => x.SomeProperty2);

The same can be written with all separate statements:

Query.Where(x => x.Name == "Something")
Query.Paginate(10, 20)
Query.Include(x => x.SomeProperty1)
          .ThenInclude(x => x.SecondLevelProperty1)
          .ThenInclude(x => x.ThirdLevelProperty1);
Query.Include(x => x.SomeProperty2);
Query.OrderBy(x => x.SomeProperty1)
         .ThenByDescending(x => x.SomeProperty2)
         .ThenBy(x => x.SomeProperty3;

[ovation22]

Ah, ok, that makes sense. Thank you so much!

[ShadyNagy]

Hello @fiseni
is that possible? SecondLevelProperty1 and SecondLevelProperty2 from SomeProperty1 can get by this way or there is another way to get it?

Query.Where(x => x.Name == "Something")
     .Paginate(10, 20)
     .Include(x => x.SomeProperty1)
         .ThenInclude(x => x.SecondLevelProperty1)
     .Include(x => x.SomeProperty1)
         .ThenInclude(x => x.SecondLevelProperty2);

[fiseni]

Hey @ShadyNagy

Yes, that's the correct way of doing it. Even when working with EF directly, you still have to do it that way, starting from the main navigation once again.

PS. This issue is old, At that time we couldn't use Include after ThenInclude and you had to start with Query again. But, we fixed that (I think since version 6.0) and your code works now. Now it looks the same as you would have written it with EF directly.

[ShadyNagy]

@fiseni Thanks so much
I will try to see how the EF will translate this code to SQL :)