CODEWITHSUNDEEP
c#asp.net-mvclinq
Diin
Diin

Reputation: 585

Using linq to filter a list from a list

I am generating two lists with int values and select all ids of list one not found in list 2 using linq:

var clerkRole = db.Roles.SingleOrDefault(m => m.Name == "Clerk");
List<ApplicationUser>lstUser = db.Users.Where(x => x.Roles.Select(y => y.RoleId).Contains(clerkRole.Id)).ToList();
List<int> lstUId = lstUser.Select(c => c.Id).ToList();

var alldps = db.Deposits.Select(a => a.UserId).Distinct().ToList();

var clerkNotIn = lstUId.Except(alldps).ToList();  // error here and below

I get the following error:

Error 25 'System.Collections.Generic.List' does not contain a definition for 'Except' and the best extension method overload 'System.Linq.ParallelEnumerable.Except(System.Linq.ParallelQuery, System.Collections.Generic.IEnumerable)' has some invalid arguments

Could you help? thanks

Upvotes: 0

Views: 125

Answers (1)

AaronLS
AaronLS

Reputation: 38392

I'm betting you are missing the Linq namespace, add this at the beginning:

using System.Linq;

Also change the var to be sure that UserId is an int. This won't have any effect except if UserId is not actually an int, then you'll get an error indicating UserId is not an int:

List<int> alldps = db.Deposits.Select(a => a.UserId).Distinct().ToList();

Upvotes: 2

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