Question

I’ve a little problem: I would insert a condition into my QueryOver that checks also the variable value. Something like this:

 var qOver = QueryOver.Of<MyModel>(() => myMod)
                .JoinAlias(() => myMod.SubMod, () => subMod, JoinType.LeftOuterJoin)
                    .Where(Restrictions.Or(
                        Restrictions.On(() => myMod.ID).IsIn(MyIDList)
                        , Restrictions.On(MyIDList == null))

In SQL sintax something like

WHERE @Variable = '' OR MyTable.MyField = @Variable

So, if I my variable is filled I’ll filter on my field. If my variable is empty (or null) I’ll select every record without filter any content.

How can I reach this result using QueryOver and Restrinctions?
Thank you!

Answer 1

If the variable is null or not set, dont add it to your query.

var qOver = QueryOver.Of<MyModel>(() => myMod)
    .JoinAlias(() => myMod.SubMod, () => subMod, JoinType.LeftOuterJoin);

if( MyIDList != null )
    qOver = qOver.Where(Restrictions.Or(Restrictions.On(() => myMod.ID).IsIn(MyIDList))