Xtensive.Orm.BulkOperations 7.1.2

Xtensive.Orm.BulkOperations

Summary

The extension provides a set of IQueryable extension methods that are translated to server-side UPDATE or DELETE commands.

Prerequisites

DataObjects.Net 7.1.x (http://dataobjects.net)

Examples of usage

Example #1. Update primitive property with a constant value:

  session.Query.All<Bar>()
    .Where(a => a.Id == 1)
    .Set(a => a.Count, 2)
    Update();

Example #2 Updating persistent property with expression, computed on server:

  session.Query.All<Bar>()
    .Where(a => a.Id==1)
    .Set(a => a.Count, a => a.Description.Length)
    .Update();

Example #3. Setting a reference to an entity that is already loaded into current Session

  // Emulating entity loading
  var bar = session.Query.Single<Bar>(1);

  session.Query.All<Foo>()
    .Where(a => a.Id == 2)
    .Set(a => a.Bar, bar)
    .Update();

Example #4. Setting a reference to an entity that is not loaded into Session, 1st way

  session.Query.All<Foo>()
    .Where(a => a.Id == 1)
    .Set(a => a.Bar, a => Query.Single<Bar>(1))
    .Update();

Example #5. Setting a reference to an entity that is not loaded into Session, 2nd way

  session.Query.All<Foo>()
    .Where(a => a.Id == 1)
    .Set(a => a.Bar, a => Query.All<Bar>().Single(b => b.Name == "test"))
    .Update();

Example #6. Constructing update expressions of the fly

  bool condition = CheckCondition();
  var query = session.Query.All()<Bar>
    .Where(a => a.Id == 1)
    .Set(a => a.Count, 2);

  if(condition)
    query = query.Set(a => a.Name, a => a.Name + "test");
  query.Update();

Example #7. Updating lots of properties at once

  session.Query.All<Bar>()
    .Where(a => a.Id == 1)
    Update(
      a => new Bar(null) { Count = 2, Name = a.Name + "test", /*dozens of other properties...*/ });

Example #8. Deleting entities

  session.Query.All<Foo>()
    .Where(a => a.Id == 1)
    .Delete();