Comments on: Interesting LINQ side affect, Pass in empty List using Contains and Get Where 0 == 1. Hmm

By: Cruz Davolt

Cruz Davolt — Fri, 02 Sep 2011 23:44:24 +0000

http://www.timeforremodelling.com/how-to-remodel-a-basement-basement-remodeling-drywall

By: gunteman

gunteman — Tue, 16 Jun 2009 20:45:57 +0000

@peter: OK!

@Damien: I’m not sure I follow..

By: Damien Guard

Damien Guard — Tue, 16 Jun 2009 00:12:11 +0000

Whenever you see 1=0 in the TSQL LINQ to SQL generates it means it believes you are testing something that can’t be nullable with something that must be nullable…

[)amien

By: peter kellner

peter kellner — Mon, 15 Jun 2009 22:19:49 +0000

yes, I agree LINQ handles it correctly. It just tricked me some so I thought i’d post it in case someone else runs into the same issue. It’s certainly not obvious.

By: gunteman

gunteman — Mon, 15 Jun 2009 22:01:38 +0000

I think Linq2Sql handles it correctly. The only other way of handling it would be to not execute the query at all, since it will never return anything, but I don’t think we can expect that since

1. The absence of a query execution could indicate a problem
2. The query may be a subquery
3. It’s not up to the Linq2Sql provider to perform any query logic

SQL Server will see that the query can’t return any results, so there will be exactly zero I/O cost.