queryover and (x like 'a' or y like 'a')

问题

Hi Is there any elegant way of combining 'like' and 'or' when i'm using queryover API? for 'like' there is something like:

 query.WhereRestrictionOn(x=>x.Code).IsLike(codePart)

for 'or' i can do something like:

query.Where( x=>x.Code == codePart || x.Description== codePart)

but how can I create a query like this:

select * from n where code like '%abc%' or description like '%abc%'

回答1:

query.Where(Restrictions.On<Type>(x => x.Code).IsLike(codePart) ||
            Restrictions.On<Type>(x => x.Description).IsLike(codePart))

回答2:

You could use the NHibernate Disjunction class to do this in a more elegant (IMHO) fashion:

var disjunction= new Disjunction();

disjunction.Add(Restrictions.On<Type>(e => e.Code).IsLike(codePart));
disjunction.Add(Restrictions.On<Type>(e => e.Description).IsLike(codePart));
//(and so on)

and then:

query.Where(disjunction)

Each "OR" is a separate instruction, which helps if you want to add the predicates conditionally.

回答3:

Another version of this, which depending on taste, you may like, is as follows:

query.Where(Restrictions.Disjunction()
         .Add(Restrictions.On<Type>(e => e.Code).IsLike(codePart))
         .Add(Restrictions.On<Type>(e => e.Description).IsLike(codePart)));

来源：https://stackoverflow.com/questions/4541546/queryover-and-x-like-a-or-y-like-a