Client API. The Codename One framework your app is built on: this runs on the device, not in a backend.

public final class Migrations

Object
Migrations

Versioned schema migrations for the application’s SQLite database.

Put scripts named V<version>__<description>.sql in the project’s src/main/db/migration directory. The build compiles them into the application, and one call brings whatever database the device holds up to the version this build expects:

Database db = Display.getInstance().openOrCreate("notes.db");
Migrations.migrate(db);

Each script runs once, in version order, inside a transaction, and is recorded in the flyway_schema_history table with a checksum. A script that has run is never edited: a change to the schema is a new script with a higher version.

Call this on the thread that owns the database, before anything else uses it, and not on the event dispatch thread if the scripts are large. A database that a newer build of the application already migrated is refused with MigrationException.FUTURE_SCHEMA before anything is changed, so an older build installed over newer data fails loudly instead of misreading its tables.

The same engine, scripts and history table are used by the Codename One backend.

Methods

`public static void register(MigrationSet set)`	Registers a migration set.
`public static boolean isRegistered()`	Whether any migration set is registered.
`public static` `Migrator of(Database db)`	A migrator for the application’s own set.
`public static` `Migrator of(Database db, MigrationSet set)`	A migrator for a specific set.
`public static` `MigrateResult migrate(Database db) throws IOException`	Applies every pending migration of every registered set: library sets first, the application’s own last.

Inherited methods

From Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait, clone

Method details

register

public static void register(MigrationSet set)

Registers a migration set. The build registers the application’s own; a library that keeps tables of its own registers one under its own name.

Parameters

set MigrationSet: the set to register, replacing one of the same name

isRegistered

public static boolean isRegistered()

Whether any migration set is registered.

Returns

true when migrate(Database) has something to run

of

public static Migrator of(Database db)

A migrator for the application’s own set.

Parameters

db Database: the database, owned by the caller and used from the calling thread

Returns

a migrator to configure and run

Throws

IllegalStateException: if the build found no migrations and none was registered

of

public static Migrator of(Database db, MigrationSet set)

A migrator for a specific set.

Parameters

db Database: the database, owned by the caller and used from the calling thread
set MigrationSet: the migrations to run

Returns

a migrator to configure and run

migrate

public static MigrateResult migrate(Database db)
throws IOException

Applies every pending migration of every registered set: library sets first, the application’s own last. Does nothing when no set is registered.

Parameters

db Database: the database, owned by the caller and used from the calling thread

Returns

what ran; the versions are those of the application’s own set

Throws

com.codename1.migration.MigrationException: if a migration fails or the database does not match this build
IOException: if the database fails