Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
370 views
in Technique[技术] by (71.8m points)

c# - How to include() nested child entity in linq

How do I include a child of a child entitiy?

Ie, Jobs have Quotes which have QuoteItems

var job = db.Jobs
            .Where(x => x.JobID == id)
            .Include(x => x.Quotes)
            .Include(x => x.Quotes.QuoteItems) // This doesn't work
            .SingleOrDefault();

Just to be clearer - I'm trying to retrieve a single Job item, and it's associated Quotes (one to many) and for each Quote the associated QuoteItems (One Quote can have many QuoteItems)

The reason I'm asking is because in my Quote Index view I'm trying to show the Total of all the Quote items for each Quote by SUMming the Subtotal, but it's coming out as 0. I'm calling the Subtotal like this:

@item.QuoteItem.Sum(p => p.Subtotal)

I believe the reason I have this issue is that my Linq query above isn't retrieving the associated QuoteItems for each Quote.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

To get a job and eager load all its quotes and their quoteitems, you write:

var job = db.Jobs
        .Include(x => x.Quotes.Select(q => q.QuoteItems))
        .Where(x => x.JobID == id)
        .SingleOrDefault();

You might need SelectMany instead of Select if QuoteItems is a collection too.

Note to others; The strongly typed Include() method is an extension method so you need to include using System.Data.Entity; at the top of your file.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...