Question

I have a SQL Server table that contains the following fields:

• SessionId (guid)
• Message (varchar)
• Timestamp (datetime)

What I need to do is to pull out the FIRST record for EACH SessionId using LINQ to SQL (ideally as a lambda, but query syntax would be useful)

It’s relatively simple to do this with t-SQL….

SELECT al.Message, al.SessionId, al.Timestamp
FROM AppLog AS al
WHERE al.Timestamp = 
(select MIN(al2.Timestamp) from ApplicationLog as al2 where al2.SessionId = al.SessionId)

I’ve tried to do the same with a Lambda query (using joins) but it’s just not working…

Any/all help will be much appreciated.

Thanks in advance

Griff

Answer 1

I don’t know if I’m being simplistic– but if this is one table, then this should work?

db.Applog.GroupBy(a=>a.SessionID).Select(g=>g.OrderBy(m=>m.Timestamp).First());