Databases
StackOverflow2013
Postsdbo
PORepository.Update strategy using EF4 Code First?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PORepository.Update strategy using EF4 Code First?
    primarykey
    data
    text
    <p>I'm working on an MVC site with Entity Framework Code First, using Ninject for DI to the controllers, and I've run into a design question. I've seen two methods used for updates with Code First. The first uses a "get by id," changes the values of the object returned, then calls <code>Context.SaveChanges()</code>, like this:</p> <p>Controller:</p> <pre><code>[HttpPost] public ActionResult Edit(int id, FormCollection collection) { //Create a vm to hold the data from the form. var sectionVm = new SectionEditViewModel(); //Copy the data from the http header to the object. UpdateModel(sectionVm); //Get the object from the database. //_sectionRepository is injected in to the constructor. var section = _sectionRepository.GetById(sectionVm.SectionId); //Map from the view model to the actual model. var viewSection = Mapper.Map(sectionVm, section); _sectionRepository.Update(); return RedirectToAction("Index"); } </code></pre> <p>Repository:</p> <pre><code> public void Update() { _context.SaveChanges(); } </code></pre> <p>The second method creates the model object, attaches it to the context, changes the state of the object, then calls <code>SaveChanges()</code>. Illustrated here with a test method as the consumer: Test:</p> <pre><code> [TestMethod] public void CanUpdateSection() { var repo = new SectionRepository(); var testSection = GetMockSection(); testSection.SomeProperty = "A new value"; testContact.AnotherProperty = "Another new value"; repo.Update(testSection); var persistedUpdatedSection = repo.GetById(testSection.Id); Assert.IsNotNull(persistedUpdatedSection); CompareSections(testSection, persistedUpdatedSection); } </code></pre> <p>Repository:</p> <pre><code> public void Update(Section entity) { using(var context = new SectionContext()) { context.Sections.Attach(entity); context.Entry(entity).State = System.Data.EntityState.Modified; context.SaveChanges(); } } </code></pre> <p>Which way is preferable, or is there another, better way?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAJ.
    1. USDean
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. PORepository.Update strategy using EF4 Code First?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PORepository.Update strategy using EF4 Code First?
      1. USAJ.
      1. VTFavorite
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload