Select an expression with nhibernate queryover

Question

using nHibernate QueryOver I want to select a series of values that include an aggregate expression. So the sql might be:

SELECT SUM(Total / (TaxRate + 1)) Totals FROM Contract Group By CustomerId

I can't see where (or if) this is supported. It seems odd that I can write where clauses as expressions but not define columns in the select as expressions.

Another way is to write a view that has the calculations and map from that — Rippo

Baz1nga Baz1nga · Accepted Answer · 2012-04-13T06:24:35

Since I dont have your code I cant verify any of this but you can try this:

var dividePropertyProjection = Projections.SqlProjection(
                "SUM(Total/TaxRate+1) as Totals", new string[] {"Totals"}, new IType[] {NHibernateUtil.Decimal});  //Assuming the sum is decimal, you can change it



var list=   Session.QueryOver<Contract>().Select(Projections.Group<Contract>(x=>x.CustomerId),dividePropertyProjection).List();

Not sure what list will return, I am guessing it should return CustomerId, Sum combination.

Hope that helps

Select an expression with nhibernate queryover

1 Answers