Question

I’ve encountered a little problem selecting only the needed model in QueryOver.
Here my scenario

 var qOver = _HibSession.QueryOver<ModelA>(() => Ma)
                .JoinAlias(() => Ma.MbList, () => Mb, JoinType.LeftOuterJoin)
                    .Where(() => Mb.ID == _MbId)
                .JoinAlias(() => Mb.McList, () => Mc,JoinType.LeftOuterJoin)                    
                    .Where(() => Mc.ID == _McId)
                .JoinAlias(() => Mc.MdList, () => Md, JoinType.LeftOuterJoin)
                    .Where(() => Md.ID == _MdID)                                             
                .OrderByAlias(() => Ma.ID).Asc
                .Take(iTake)
                .Skip(iSkip)
                .Future<ModelA>();

The previous code generate the follow SQL

SELECT TOP n Ma.*,Mb.*,Mc.*,Md.*
FROM Ma 
LEFT JOIN Mb ON (...conditions...)
LEFT JOIN Mc ON (...conditions...)
LEFT JOIN Md ON (...conditions...)
WHERE Mb.ID = _MbId
AND Mc.ID = _McId
AND Md.ID = _MdId
ORDER BY Ma.ID ASC

The problem is that Mc and Md table duplicates my result. So I would have only Ma and Mb in my SELECT statement.

SELECT TOP n Ma.*,Mb.*
FROM
.
.
.

How can I reach that result?
Thank you!

Answer 1

It seems the only way is to use a pricipal QueryOver selecting the main model and a filtered SubQuery

I mean something like this

var qOverInclude = QueryOver.Of<MyModel>(() => mModel)
                .JoinAlias(() => mModel.MyList, () => mList, JoinType.LeftOuterJoin)
                    .Where(() => mList.ID == myID)
                    .And(() => mList.Type == myType)
                .Select(x => x.IdMyModel);

  var qOver = _HibSession.QueryOver<MyModel>(() => mModel)
                .JoinAlias(() => mModel.MyDescription, () => mDescription, JoinType.LeftOuterJoin)
                .Where(() => mDescription.IDLanguage == myLanguage)
                .WithSubquery.WhereProperty(() => mModel.IdMyModel).In(qOverSubQuery)
                .OrderByAlias(() => mModel.IdMyModel).Asc
                .Future<MyModel>();