How to use NHibernate's ICriteria for grouping, fetching associations and T-SQL functions - tsql

Question

I want to create the following T-SQL statement:
SELECT SUM (sa.Amount) as 'SumAmount',
SUM(sa.Cost) as 'SumCost',
gg.[Description] as 'Goodsgroup', Month(sa.[Date]) as 'Month'
FROM SalesmanArticle sa
INNER JOIN Article a
ON a.ArticleId = sa.ArticleId
INNER JOIN GoodsGroup gg
ON gg.GoodsGroupId = a.GoodsGroupId
GROUP BY gg.[Description], Month(sa.[Date])
ORDER BY 'Month', 'Goodsgroup'
Is this possible with NHibernates ICriteria?
How can I use the Month-T-SQL-Function?
Do I have to join manually or does the ICriteria API knows that when I use the propetyName 'SalesmanArticle.Article.Goodsgroup.Description' it has to join the Article and the Goodsgroup?
EDIT:
For now I have written this code here:
// typesafe properties
string article = typeof(Article).Name;
string goodsGroup = typeof(GoodsGroup).Name;
string salesmanArticle = typeof(SalesmanArticle).Name;
string amount = Reflector.GetPropertyName<SalesmanArticle>(x => x.Amount);
string cost = Reflector.GetPropertyName<SalesmanArticle>(x => x.Cost);
string description = string.Format("{0}.{1}",
goodsGroup, Reflector.GetPropertyName<SalesmanArticle>(x => x.Article.GoodsGroup.Description));
string date = Reflector.GetPropertyName<SalesmanArticle>(x => x.Date);
string formatedDate = string.Format("MONTH([{0}])", date);
return GetSession()
// FROM
.CreateCriteria(typeof(SalesmanArticle), salesmanArticle)
// JOIN
.CreateCriteria(article, article, JoinType.InnerJoin)
.CreateCriteria(goodsGroup, goodsGroup, JoinType.InnerJoin)
// SELECT
.SetProjection(Projections.ProjectionList()
.Add(Projections.Sum(amount))
.Add(Projections.Sum(cost))
// GROUP BY
.Add(Projections.GroupProperty(description))
.Add(Projections.SqlGroupProjection(formatedDate, formatedDate, new[]{"MyDate"} , new[] { NHibernateUtil.Int32 })))
.List();
But an AdoException is thrown:
could not execute query [ SELECT
sum(this_.Amount) as y0_,
sum(this_.Cost) as y1_,
goodsgroup2_.Description as y2_,
MONTH([Date]) FROM [SalesmanArticle]
this_ inner join [Article] article1_
on this_.ArticleId=article1_.ArticleId
inner join [GoodsGroup] goodsgroup2_
on
article1_.GoodsGroupId=goodsgroup2_.GoodsGroupId
GROUP BY goodsgroup2_.Description,
MONTH([Date]) ]
[SQL: SELECT
sum(this_.Amount) as y0_,
sum(this_.Cost) as y1_,
goodsgroup2_.Description as y2_,
MONTH([Date]) FROM [SalesmanArticle]
this_ inner join [Article] article1_
on this_.ArticleId=article1_.ArticleId
inner join [GoodsGroup] goodsgroup2_
on
article1_.GoodsGroupId=goodsgroup2_.GoodsGroupId
GROUP BY goodsgroup2_.Description,
MONTH([Date])]
The strange thing is that NHibernate tries to create 2 queries?!
AND BOTH of them are correct!
Instead of the codeline
.Add(Projections.SqlGroupProjection(formatedDate, formatedDate, new[]{"MyDate"} , new[] { NHibernateUtil.Int32 })))
I used
.Add(Projections.SqlFunction("MONTH", NHibernateUtil.Int32, Projections.GroupProperty(date))))
The problem with the SqlFunction is that it creates a GROUP BY sa.Date instead of MONTH(sa.Date). But this method worked syntactically correct.
So I switched to the SqlGroupProjection method.
But anyway it does not work.
Can anybody help me?

Answer 1

I solved it. Here is the correct code:
public class SalesmanArticleRepository : Repository<SalesmanArticle>, ISalesmanArticleRepository
{
public IList GetAllAll()
{
// typesafe properties
string article = typeof(Article).Name;
string goodsGroup = typeof(GoodsGroup).Name;
string salesmanArticle = typeof(SalesmanArticle).Name;
string amount = Reflector.GetPropertyName<SalesmanArticle>(x => x.Amount);
string cost = Reflector.GetPropertyName<SalesmanArticle>(x => x.Cost);
string description = string.Format("{0}.{1}",
goodsGroup, Reflector.GetPropertyName<SalesmanArticle>(x => x.Article.GoodsGroup.Description));
string date = Reflector.GetPropertyName<SalesmanArticle>(x => x.Date);
string formatedDateSql = string.Format("month({{alias}}.[{0}]) as mydate", date);
string formatedDateGroupBy = string.Format("month({{alias}}.[{0}])", date);
return GetSession()
// FROM
.CreateCriteria(typeof(SalesmanArticle), salesmanArticle)
// JOIN
.CreateCriteria(article, article, JoinType.InnerJoin)
.CreateCriteria(goodsGroup, goodsGroup, JoinType.InnerJoin)
// SELECT
.SetProjection(Projections.ProjectionList()
.Add(Projections.Sum(amount))
.Add(Projections.Sum(cost))
// GROUP BY
.Add(Projections.GroupProperty(description))
.Add(Projections.SqlGroupProjection(formatedDateSql, formatedDateGroupBy, new[] { "mydate" }, new[] { NHibernateUtil.Int32 })))
.List();
}
}