# Database Initialisers
# CreateDatabaseIfNotExists
Implementation of IDatabaseInitializer
that is used in EntityFramework by default. As the name implies, it creates the database if none exists.
However when you change the model, it throws an exception.
Usage:
public class MyContext : DbContext {
public MyContext() {
Database.SetInitializer(new CreateDatabaseIfNotExists<MyContext>());
}
}
# DropCreateDatabaseIfModelChanges
This implementation of IDatabaseInitializer
drops and recreates the database if the model changes automatically.
Usage:
public class MyContext : DbContext {
public MyContext() {
Database.SetInitializer(new DropCreateDatabaseIfModelChanges<MyContext>());
}
}
# DropCreateDatabaseAlways
This implementation of IDatabaseInitializer
drops and recreates the database everytime your context is used in applications app domain. Beware of the data loss due to the fact, that the database is recreated.
Usage:
public class MyContext : DbContext {
public MyContext() {
Database.SetInitializer(new DropCreateDatabaseAlways<MyContext>());
}
}
# Custom database initializer
You can create your own implementation of IDatabaseInitializer
.
Example implementation of an initializer, that will migrate the database to 0 and then migrate all the way to the newest migration (usefull e.g. when running integration tests). In order to do that you would need a DbMigrationsConfiguration
type too.
public class RecreateFromScratch<TContext, TMigrationsConfiguration> :
IDatabaseInitializer<TContext>
where TContext : DbContext
where TMigrationsConfiguration : DbMigrationsConfiguration<TContext>, new()
{
private readonly DbMigrationsConfiguration<TContext> _configuration;
public RecreateFromScratch()
{
_configuration = new TMigrationsConfiguration();
}
public void InitializeDatabase(TContext context)
{
var migrator = new DbMigrator(_configuration);
migrator.Update("0");
migrator.Update();
}
}
# MigrateDatabaseToLatestVersion
An implementation of IDatabaseInitializer
that will use Code First Migrations to update the database to the latest version. To use this initializer you have to use DbMigrationsConfiguration
type too.
Usage:
public class MyContext : DbContext {
public MyContext() {
Database.SetInitializer(
new MigrateDatabaseToLatestVersion<MyContext, Configuration>());
}
}