Migration
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abstract class Migration
Base class for a database migration.
Each migration can move between 2 versions that are defined by startVersion and endVersion.
A migration can handle more than 1 version (e.g. if you have a faster path to choose when going version 3 to 5 without going to version 4). If Room opens a database at version 3 and latest version is 5, Room will use the migration object that can migrate from 3 to 5 instead of 3 to 4 and 4 to 5.
If there are not enough migrations provided to move from the current version to the latest version, Room will might clear the database and recreate if destructive migrations are enabled.
Summary
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Creates a new migration between |
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abstract suspend Unit |
migrate(connection: SQLiteConnection)Should run the necessary migrations. |
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Public constructors
Migration
Migration(startVersion: Int, endVersion: Int)
Creates a new migration between startVersion and endVersion inclusive.
Public functions
migrate
abstract suspend fun migrate(connection: SQLiteConnection): Unit
Should run the necessary migrations.
This function is already called inside a transaction and that transaction might actually be a composite transaction of all necessary Migrations.
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connection: SQLiteConnection |
The database connection |