Save detached entity in Entity Framework 6

by

Yes, this is correct. This article describes various ways of adding and attaching entities, and it provides this example:

var existingBlog = new Blog { BlogId = 1, Name = "ADO.NET Blog" };
using (var context = new BloggingContext())
{
    // The next step implicitly attaches the entity
    context.Entry(existingBlog).State = EntityState.Modified;
    // Do some more work...
    context.SaveChanges();
}

Since EF doesn’t know which properties are different from those in the database, it will update them all:

When you change the state to Modified all the properties of the entity will be marked as modified and all the property values will be sent to the database when SaveChanges is called.

To avoid this, you can set which properties are modified manually rather than setting the entire entity state:

using (var context = new BloggingContext())
{
    var blog = context.Blogs.Find(1);
    context.Entry(blog).Property(u => u.Name).IsModified = true;     
    // Use a string for the property name
    context.Entry(blog).Property("Name").IsModified = true;
}

More Related Contents:

  1. Entity Framework Provider type could not be loaded?
  2. How to update record using Entity Framework 6?
  3. How to filter “Include” entities in entity framework?
  4. EF Code-First One-to-one relationship: Multiplicity is not valid in Role * in relationship
  5. Entity Framework 6 GUID as primary key: Cannot insert the value NULL into column ‘Id’, table ‘FileStore’; column does not allow nulls
  6. Mapping composite keys using EF code first
  7. Setting unique Constraint with fluent API?
  8. Lazy Loading vs Eager Loading
  9. Entity Framework 6: audit/track changes
  10. Dynamic MySQL database connection for Entity Framework 6
  11. Entity Framework 6 Code First Custom Functions
  12. DbSet.Attach(entity) vs DbContext.Entry(entity).State = EntityState.Modified
  13. Problems using Entity Framework 6 and SQLite
  14. Database.BeginTransaction vs Transactions.TransactionScope [duplicate]
  15. Eager , Lazy and explicit loading in EF6
  16. Configure multiple database Entity Framework 6
  17. Entity Framework 6 transaction rollback
  18. Log Queries executed by Entity Framework DbContext
  19. How are people unit testing with Entity Framework 6, should you bother?
  20. Async PartialView causes “HttpServerUtility.Execute blocked…” exception
  21. How to group by DateTime.Date in EntityFramework
  22. How to use String property as primary key in Entity Framework
  23. How does the SQLite Entity Framework 6 provider handle Guids?
  24. How can set a default value constraint with Entity Framework 6 Code First?
  25. MSSQL Error ‘The underlying provider failed on Open’
  26. Method cannot be translated into a store expression
  27. LINQ to Entities only supports casting EDM primitive or enumeration types with IEntity interface
  28. EF5 Getting this error message: Model compatibility cannot be checked because the database does not contain model metadata
  29. Why is EF returning a proxy class instead of the actual entity?
  30. System.Data.Entity.Core.EntityCommandExecutionException Occurred in MVC app Using EF

Leave a Comment