SupportSQLiteOpenHelper.Callback

abstract class SupportSQLiteOpenHelper.Callback


Creates a new Callback to get database lifecycle events.

Handles various lifecycle events for the SQLite connection, similar to room-runtime.SQLiteOpenHelper.

Summary

Public constructors

Callback(version: Int)

Public functions

open Unit

Called when the database connection is being configured, to enable features such as write-ahead logging or foreign key support.

open Unit

The method invoked when database corruption is detected.

abstract Unit

Called when the database is created for the first time.

open Unit
onDowngrade(db: SupportSQLiteDatabase, oldVersion: Int, newVersion: Int)

Called when the database needs to be downgraded.

open Unit

Called when the database has been opened.

abstract Unit
onUpgrade(db: SupportSQLiteDatabase, oldVersion: Int, newVersion: Int)

Called when the database needs to be upgraded.

Public properties

Int

Version number of the database (starting at 1); if the database is older, Callback.onUpgrade will be used to upgrade the database; if the database is newer, Callback.onDowngrade will be used to downgrade the database.

Public constructors

Callback

Added in 2.0.0
Callback(version: Int)

Public functions

onConfigure

Added in 2.0.0
open fun onConfigure(db: SupportSQLiteDatabase): Unit

Called when the database connection is being configured, to enable features such as write-ahead logging or foreign key support.

This method is called before onCreate, onUpgrade, onDowngrade, or onOpen are called. It should not modify the database except to configure the database connection as required.

This method should only call methods that configure the parameters of the database connection, such as SupportSQLiteDatabase.enableWriteAheadLogging, SupportSQLiteDatabase.setLocale, SupportSQLiteDatabase.setMaximumSize, or executing PRAGMA statements.

Parameters
db: SupportSQLiteDatabase

The database.

onCorruption

Added in 2.0.0
open fun onCorruption(db: SupportSQLiteDatabase): Unit

The method invoked when database corruption is detected. Default implementation will delete the database file.

Parameters
db: SupportSQLiteDatabase

the SupportSQLiteDatabase object representing the database on which corruption is detected.

onCreate

Added in 2.0.0
abstract fun onCreate(db: SupportSQLiteDatabase): Unit

Called when the database is created for the first time. This is where the creation of tables and the initial population of the tables should happen.

Parameters
db: SupportSQLiteDatabase

The database.

onDowngrade

Added in 2.0.0
open fun onDowngrade(db: SupportSQLiteDatabase, oldVersion: Int, newVersion: Int): Unit

Called when the database needs to be downgraded. This is strictly similar to onUpgrade method, but is called whenever current version is newer than requested one. However, this method is not abstract, so it is not mandatory for a customer to implement it. If not overridden, default implementation will reject downgrade and throws SQLiteException

This method executes within a transaction. If an exception is thrown, all changes will automatically be rolled back.

Parameters
db: SupportSQLiteDatabase

The database.

oldVersion: Int

The old database version.

newVersion: Int

The new database version.

onOpen

Added in 2.0.0
open fun onOpen(db: SupportSQLiteDatabase): Unit

Called when the database has been opened. The implementation should check SupportSQLiteDatabase.isReadOnly before updating the database.

This method is called after the database connection has been configured and after the database schema has been created, upgraded or downgraded as necessary. If the database connection must be configured in some way before the schema is created, upgraded, or downgraded, do it in onConfigure instead.

Parameters
db: SupportSQLiteDatabase

The database.

onUpgrade

Added in 2.0.0
abstract fun onUpgrade(db: SupportSQLiteDatabase, oldVersion: Int, newVersion: Int): Unit

Called when the database needs to be upgraded. The implementation should use this method to drop tables, add tables, or do anything else it needs to upgrade to the new schema version.

The SQLite ALTER TABLE documentation can be found here. If you add new columns you can use ALTER TABLE to insert them into a live table. If you rename or remove columns you can use ALTER TABLE to rename the old table, then create the new table and then populate the new table with the contents of the old table.

This method executes within a transaction. If an exception is thrown, all changes will automatically be rolled back.

Parameters
db: SupportSQLiteDatabase

The database.

oldVersion: Int

The old database version.

newVersion: Int

The new database version.

Public properties

version

Added in 2.0.0
val versionInt

Version number of the database (starting at 1); if the database is older, Callback.onUpgrade will be used to upgrade the database; if the database is newer, Callback.onDowngrade will be used to downgrade the database.