How would I use Linq-To-Nhibernate (NH3.2) to have the database return to me the record count of a query without the records themselves?

Question

I have a bunch of queries to run, and if any of them return even a single result, I toggle a boolean variable true. If they all return no results, then it stays false.

Right now I'm just picking the smallest column and .Select() ing it, and then counting the results locally. But is there a way to have the database send back a single integer representing the record count of the query through linq-to-nhibernate?

Thanks!

score 2 · Accepted Answer · answered Feb 14 '12 at 20:57

2

Using the Query API, it would be

return Session.QueryOver<YourType>().RowCount();

or for Int64 (bigint)

return Session.QueryOver<YourType>().RowCountInt64();

If you're sending multiple queries, then you could use futures to batch all the queries together.

answered Feb 14 '12 at 20:57

Russ Cam

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So this isn't implemented in the Linq provider yet? – Isaac Bolinger Feb 14 '12 at 21:02
I think it is (can't test at the moment and usually use the Query API), `Session.Query().Count();` with LINQ to NHibernate – Russ Cam Feb 14 '12 at 21:12
I guess I could put the .Count at the end and see what kind of query NH throws out. – Isaac Bolinger Feb 14 '12 at 21:13
Adding the .Count() at the end works fine. The sql has "select cast(count(*) as INT)" in the front. – Isaac Bolinger Feb 14 '12 at 21:19

How would I use Linq-To-Nhibernate (NH3.2) to have the database return to me the record count of a query without the records themselves?

1 Answers1