CODEWITHSUNDEEP
c#linqlinq-to-sql
user348173
user348173

Reputation: 9278

find records by criteria and select only one if they have some equal field (LINQ)

I have a class BaseEvent and it have the following fields:

Name, RecurrenceStart, RecurrenceEnd, SimillarId

For example we have a data in a table:

Name           RecurrenceStart                RecurrenceEnd          SimillarId 
Event1      2012-02-21 09:00:00.000      2012-02-28 11:30:00.000        1
Event1      2012-02-21 04:30:00.000      2012-02-28 07:00:00.000        1
Event2      2012-02-21 06:30:00.000      2012-02-29 09:00:00.000        2

And we have the following query:

   var today = DateTime.Now;
    return  Database.BaseEvents.Where(e => e.RecurrenceStart.Value.Date <= today 
             && e.RecurrenceEnd.Value.Date >= today).ToList();

The query return all 3 records(for current date). But the first two record is the same event. I want that in the result will only two records: 3 and (1 or 2).
How can I do this?
Thanks.

P.S. I was introduce SimillarId for this purpose, but I don't know how to build a query with it or not.

P.S.2. Change question name if it necessery.

Upvotes: 0

Views: 184

Answers (2)

Niranjan Singh
Niranjan Singh

Reputation: 18290

Try this:

var today = DateTime.Now; 
    return  Database.BaseEvents.Where(e => e.RecurrenceStart.Value.Date <= today  
             && e.RecurrenceEnd.Value.Date >= today)
            .GroupBy(v => v.Name).Select(g => g.First()).ToList();

Upvotes: 1

BlueM
BlueM

Reputation: 6888

Use .Distinct() with an IEqualityComparer<BaseEvent> as argument which you have to implement first.

Upvotes: 2

Related Questions