How to build a nested query with the dynamic LINQ library

Question

How can I build the following LINQ query with the Dynamic Linq library (System.Linq.Dynamic)?

var roles = rolesCollection.Where(r => r.AssignedUsers.Where(u => u.Name.FirstName == "Patrick").Count() > 0);

rolesCollection and AssignedUsers are collections which implement the IEnumerable interface.

I was thinking about doing something like this:

rolesCollection.Where("AssignedUsers.Where(\"Name.FirstName == 'Patrick'\").Count() > 0");

But that doesn't work. A ParseException with the message "No applicable aggregate method 'Where' exists" is thrown.

Thanks in advance.

score 7 · Accepted Answer · edited Dec 22 '14 at 16:36

7

Try this:

rolesCollection
    .Where("AssignedUsers.Where(Name.FirstName == \"Patrick\").Any()");

or

var userName = "Patrick";
rolesCollection
    .Where("AssignedUsers.Where(Name.FirstName == @0).Any()", userName);

edited Dec 22 '14 at 16:36

DontVoteMeDown

answered Apr 25 '12 at 11:38

Adrian Iftode

Dude you just saved me ! Cant figure out this linq and the docs aren't really complete. Where can i learn more about its queries ? – Ariel Apr 06 '16 at 18:02
1

Check out the docs+example code at http://system-linq-dynamic-core.azurewebsites.net/html/a5ecbe15-aade-af7f-4860-6c5c412a34b4.htm – Stef Heyenrath Jun 14 '16 at 16:17

1 Answers1