C#

Yesterday I blogged about how to delete a detached entity using Entity Framework 5 by only using its Id. A common practice in many applications today is to not actually delete the entity from the database, but instead mark it as deleted and make sure your data access layer filters out those “deleted” items when selecting. So I wanted to implement a general “delete” method that would update the DateDeleted column of an entity without touching any other column. Again I use a detached entity, so the trick is to only mark the DateDeleted column as modified, and not the entire entity. public bool DeleteEntity(T entity) where T : ModelBase { entity.DateDeleted = DateTime.UtcNow; this._databaseContext.Set().Attach(entity); this._databaseContext.Configuration.ValidateOnSaveEnabled = false; this._databaseContext.Entry(entity).Property(m => m.DateDeleted).IsModified = true; int recordsAffected = this._databaseContext.SaveChanges(); this._databaseContext.Configuration.ValidateOnSaveEnabled = true; return recordsAffected == 1; } Notice how I disable validation, and … Continued

Entity Framework 5, with the Code First approach can do some pretty powerful things without much effort. Create your model classes, and it spins up a brand new and shiny database for you. But sometimes you do need to tweak a few things in order to achieve what you want. For example, I don’t want to load an entity before I can delete it. What’s the point? Say I have a list of Accounts on a webpage, with a shiny delete button that makes an AJAX call to an MVC controller, (or Backbone model, that hits the web backend). In that situation I’ll only have the Id of the entity, which should be enough to delete it. Attach, Delete To delete only by Id, you need to create a dummy instance of your model with the Id you wish to … Continued