Create and Drop APIs
The EnsureCreated and EnsureDeleted methods provide a lightweight alternative to Migrations for managing the database schema. These methods are useful in scenarios when the data is transient and can be dropped when the schema changes. For example during prototyping, in tests, or for local caches.
Some providers (especially non-relational ones) don't support Migrations. For these providers, EnsureCreated is often the easiest way to initialize the database schema.
EnsureCreated and Migrations don't work well together. If you're using Migrations, don't use EnsureCreated to initialize the schema.
Transitioning from EnsureCreated to Migrations is not a seamless experience. The simplest way to do it is to drop the database and re-create it using Migrations. If you anticipate using migrations in the future, it's best to just start with Migrations instead of using EnsureCreated.
The EnsureDeleted method will drop the database if it exists. If you don't have the appropriate permissions, an exception is thrown.
// Drop the database if it exists dbContext.Database.EnsureDeleted();
EnsureCreated will create the database if it doesn't exist and initialize the database schema. If any tables exist (including tables for another DbContext class), the schema won't be initialized.
// Create the database if it doesn't exist dbContext.Database.EnsureCreated();
Async versions of these methods are also available.
To get the SQL used by EnsureCreated, you can use the GenerateCreateScript method.
var sql = dbContext.Database.GenerateCreateScript();
Multiple DbContext classes
EnsureCreated only works when no tables are present in the database. If needed, you can write your own check to see if the schema needs to be initialized, and use the underlying IRelationalDatabaseCreator service to initialize the schema.
// TODO: Check whether the schema needs to be initialized // Initialize the schema for this DbContext var databaseCreator = dbContext.GetService<IRelationalDatabaseCreator>(); databaseCreator.CreateTables();