CODEWITHSUNDEEP
.netlinqentity-framework
SiberianGuy
SiberianGuy

Reputation: 25292

Query grouped entity with max value

I have an entity BattleUser which contains four properties: Id, BattleId, UserId and DateTime. I need to query the last (by date) BattleUser entity for every user. So I came to something like this:

context.GroupBy(bu => bu.UserId, bu => bu).
Select(gbu => new { UserId = gbu.Key, DateTime = gbu.Max(bu => bu.DateTime) }).
ToList();

By this query I retrieve the last DateTime for each user. By using these values I can retrieve last BattleUser entities for every user by another query. Is there any way to modify initial query to solve the task by one query?

Upvotes: 1

Views: 236

Answers (1)

Slauma
Slauma

Reputation: 177133

You can try this query:

context.GroupBy(bu => bu.UserId, bu => bu)
    .Select(gbu => new
    {
       UserId = gbu.Key,
       LastBattleUser = gbu.OrderByDescending(bu => bu.DateTime).FirstOrDefault()
    })
    .ToList();

Upvotes: 1

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