RoomDatabase.MigrationContainer

Added in 3.0.1

Kotlin |Java

Cmn
```
class RoomDatabase.MigrationContainer
```

A container to hold migrations. It also allows querying its contents to find migrations between two versions.

Summary

Public constructors
`MigrationContainer()`	android
`MigrationContainer()`	Cmn
`MigrationContainer()`	Cmn

Public functions
`Unit`	`addMigrations(migrations: List<Migration>)` Adds the given migrations to the list of available migrations.	Cmn android
`Unit`	`addMigrations(vararg migrations: Migration)` Adds the given migrations to the list of available migrations.	android
`Boolean`	`contains(startVersion: Int, endVersion: Int)` Indicates if the given migration is contained within the `MigrationContainer` based on its start-end versions.	Cmn android
`List<Migration>?`	`findMigrationPath(start: Int, end: Int)` Finds the list of migrations that should be run to move from `start` version to `end` version.	Cmn android
`Map<Int, Map<Int, Migration>>`	`getMigrations()` Returns the map of available migrations where the key is the start version of the migration, and the value is a map of (end version -> Migration).	Cmn android

Public constructors

MigrationContainer

android

Added in 3.0.1

MigrationContainer()

MigrationContainer

Cmn

Added in 3.0.1

MigrationContainer()

MigrationContainer

Cmn

Added in 3.0.1

MigrationContainer()

Public functions

addMigrations

Cmn android

fun addMigrations(migrations: List<Migration>): Unit

Adds the given migrations to the list of available migrations. If 2 migrations have the same start-end versions, the latter migration overrides the previous one.

Parameters
`migrations: List<Migration>`	List of available migrations.

addMigrations

android

Added in 3.0.1

fun addMigrations(vararg migrations: Migration): Unit

Adds the given migrations to the list of available migrations. If 2 migrations have the same start-end versions, the latter migration overrides the previous one.

Parameters
`vararg migrations: Migration`	List of available migrations.

contains

Cmn android

Added in 3.0.1

fun contains(startVersion: Int, endVersion: Int): Boolean

Indicates if the given migration is contained within the MigrationContainer based on its start-end versions.

Parameters
`startVersion: Int`	Start version of the migration.
`endVersion: Int`	End version of the migration

Returns
`Boolean`	True if it contains a migration with the same start-end version, false otherwise.

findMigrationPath

Cmn android

Added in 3.0.1

fun findMigrationPath(start: Int, end: Int): List<Migration>?

Finds the list of migrations that should be run to move from start version to end version.

Parameters
`start: Int`	The current database version
`end: Int`	The target database version

Returns
`List<Migration>?`	An ordered list of `Migration` objects that should be run to migrate between the given versions. If a migration path cannot be found, returns `null`.

getMigrations

Cmn android

Added in 3.0.1

fun getMigrations(): Map<Int, Map<Int, Migration>>

Returns the map of available migrations where the key is the start version of the migration, and the value is a map of (end version -> Migration).

Returns
`Map<Int, Map<Int, Migration>>`	Map of migrations keyed by the start version