Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>This has proved to be a popular post so I have updated it in light of feedback from others. The main thing to know is that the Seed method in the Configuration class is run EVERY time the application starts, which isn't what the comment in the template method implies. See the answer from someone at Microsoft to this <a href="https://stackoverflow.com/questions/10822618/confusion-over-ef-auto-migrations-and-seeding-seeding-every-program-start">post</a> about why that is - thanks to Jason Learmouth for finding that.</p> <p>If you, like me, only want to run the database updates if there are any pending migrations then you need to do a bit more work. You can find that out if there are pending migrations by calling migrator.GetPendingMigrations(), but you have to do that in the ctor as the list of pending migrations is cleared before Seed method is called. The code to implement this, which goes in the Migrations.Configuration class is as follows:</p> <pre><code>internal sealed class Configuration : DbMigrationsConfiguration&lt;YourDbContext&gt; { private readonly bool _pendingMigrations; public Configuration() { // If you want automatic migrations the uncomment the line below. //AutomaticMigrationsEnabled = true; var migrator = new DbMigrator(this); _pendingMigrations = migrator.GetPendingMigrations().Any(); } protected override void Seed(MyDbContext context) { //Microsoft comment says "This method will be called after migrating to the latest version." //However my testing shows that it is called every time the software starts //Exit if there aren't any pending migrations if (!_pendingMigrations) return; //else run your code to seed the database, e.g. context.Foos.AddOrUpdate( new Foo { bar = true}); } } </code></pre> <p>I should point out that some people have suggested putting the seed code in the actual 'up' migration code. This works, but means you need to remember to put the seed code in each new migration and its pretty hard remember so I wouldn't do that. However if your seed changes with each migration then that might be the a good way to go.</p>
    singulars
    1. This table or related slice is empty.
    1. POEntity Framework 5 Migrations: Setting up an initial migration and single seed of the database
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USCommunity
    1. USJon P Smith
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POEntity Framework 5 Migrations: Setting up an initial migration and single seed of the database
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COIm guessing it runs every time because thats the only way they could do it without actually having to implement seeding into the actual migration. If your seed code was inside the Up() of a migration it would only get run once, and this is more intuitive to me, since usually you make some db changes and want to seed some data into this new part of the schema
      singulars
      1. PO
      1. USJim Wolff
    2. COIf you don't have any migrations your seed method would never be run using this method. I too nowdays prefer to do seeding in a migration - that way I know it will be run only once.
      singulars
      1. PO
      1. USoldwizard
    3. COHi pcguru. In fact you always have a migration as the initial database is considered to be a migration, i.e. it migrates from no database to having a database. However I can see the benefit of having the seed in the migration.
      singulars
      1. PO
      1. USJon P Smith
 

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