CODEWITHSUNDEEP
c#.netlinqnhibernate
user1765862
user1765862

Reputation: 14155

finding last saved id using NHibernate LINQ

Currently I'm using following code 

 var lastId = DataRepository.All().ToList().LastOrDefault().Id;

in order to find last inserted row Id

How can I refactor above code without projecting into ToList()?

DataRepository.All() returns IQuerable<T>

Upvotes: 1

Views: 331

Answers (1)

Radim K&#246;hler
Radim K&#246;hler

Reputation: 123861

It is really as easy as a HashPsi comment.

In case that your DataRepository.All() returns IQuerable<T> - all these kinds of queries will result in one simple SQL statement returning just the last Id:

// query
IQueryable<T> query = DataRepository.All();

// just MAX
var maxIdA = query
   .Max(x => x.Id);

// also this kind of construct with Take() and SingleOrDefault()
// will be effective (not loading complete list from DB to app)
// and could be used for more complex queries with unique result
var maxIdB = query
      .OrderByDescending(x => x.Id)
      .Select(x => x.Id)
      .Take(1)
      .SingleOrDefault();

Upvotes: 1

Related Questions