Databases
StackOverflow2013
Postsdbo
POShould repositories be implemented as singletons as best practice?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POShould repositories be implemented as singletons as best practice?
    primarykey
    data
    text
    <p>I have a small webapp that uses <code>EntityFramework</code> to store stuff via repositories into the database.</p> <p>What I've done so far (based on all the tutorials I read) is create a repository where I need it, as shown below:</p> <p>In <code>CustomMembershipProvider</code>:</p> <pre><code> public CustomMembershipProvider() { _userRepository = new UserRepository(new TenantApplicationContext()); } </code></pre> <p>In my <code>RegisterController</code>:</p> <pre><code> public TenantRepository TenantRepository { get; set; } public UserRepository UserRepository { get; set; } protected override void Initialize(RequestContext requestContext) { if (MembershipService == null) { MembershipService = new AccountMembershipService(); } if (TenantRepository == null) { TenantRepository = new TenantRepository(TenantApplicationContext); } if (UserRepository == null) { UserRepository = new UserRepository(TenantApplicationContext); } base.Initialize(requestContext); } </code></pre> <p>The point is, that I instantiate the <code>UserRepository</code> twice. This becomes a problem when I create a <code>User</code> in one instance, and try to retrieve it in the other instance, <strong>and I did not call</strong> <code>SaveChanges</code> in between.</p> <p>The problem lies here:</p> <pre><code>// Snippet from the register controller class if (!UserRepository.Exists(model.AccountableEmailAddress)) { // 1 - Create the user via a custom MembershipProvider // Note, the CustomMembershipProvider has it's own instance of UserRepository var createStatus = MembershipService.CreateUser( model.AccountableUser, model.Password, model.AccountableEmailAddress); if (createStatus == MembershipCreateStatus.Success) { // Left out irrelevant code AdministerUserAndTenant(tenant.Name, model.AccountableEmailAddress); } } private void AdministerUserAndTenant(string tenantName, string emailAddress) { // 2 - Try to retrieve the user from a different (!) instance of UserRepository var user = UserRepository.GetUser(emailAddress); var tenant = TenantRepository.GetTenantByName(tenantName); tenant.Users.Add(user); TenantApplicationContext.SaveChanges(); } </code></pre> <p>I hope you can still follow, tried to leave out unnecessary parts. </p> <p>What is the best way to deal with issues like this? </p> <p>PS: I'm not very fond of the <code>Singleton</code> pattern, so if possible don't go there :).</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USbas
    1. USbas
    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. This table or related slice is empty.
    1. COWhy would you? Having them as singletons doesn't solve any specific problem, does it?
      singulars
      1. POShould repositories be implemented as singletons as best practice?
      1. USOded
    2. COwell, that would solve the part where I always work with the same repository instance. So I would be able to retrieve uncommitted objects.
      singulars
      1. POShould repositories be implemented as singletons as best practice?
      1. USbas
    3. COJust centralize the access to repositories. No need to have them as singletons.
      singulars
      1. POShould repositories be implemented as singletons as best practice?
      1. USOded
 

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