Nhibernate Linq In Clause

Question

Is it possible to get Nhibernate linq to generate a query with an "In" clause? e.g. - Where AnID in (x,y,z)?

Answer 1

I don't know the state of nHibernate with respect to generating all the potential LINQ queries, but you should be able to use .Contains() to generate an IN.

var list = new int[] { x, y, x }; var q = db.Entities.Where( e => list.Contains( e.AnID ) ); 

Answer 2

Agreed, this does work. I found the generated SQL for 'not in' to be strange though (as of 3.3.0 GA)

... from   mytable t0_ where   case     when t0_.testValue in (               @p0 , @p1 , @p2           ) then 1           else 0     end=@p3 @p0 = 9 [Type: Int32 (0)], @p1 = 99 [Type: Int32 (0)], @p2 = 109 [Type: Int32 (0)], @p3 = False [Type: Boolean (0)], ... 

Seems a bit odd to 'case' this when 'not in' would have been clearer (not that I plan on reading every line, but in a trace/profile maybe).

(... later that day ...)

I realized that the above 'strange' choice of SQL was only when I used

.Where(e => list.Contains(e.AnID) == false) 

If I used

.Where(e => !list.Contains(e.AnID)) 

The SQL generated is much cleaner (using 'not in')