[feature] Programmatic migrations and/or documentation for it

Is your feature request related to a problem? Please describe. There doesn’t seem to be an “easy” way to programmatically migrate (At least not documented).

Describe the solution you’d like Something like:

val config = DbConfig()
config.migrate()

(probably a bit more complex, but at least an easy and documented API)

In that case spitting the core/API from the plugin would probably be nice too.

Describe alternatives you’ve considered I’ve tried to look at the plugin and reproduce it but it looks quite complicated.

Additional context I’m trying to use it in spring but I’d like to make migrations automatically, because (semi-)manually might not be feasible in many contexts.

[cromefire]

I’ll have a look at it

[cromefire]

So what I came up with as probably working is something like this:

fun migrate(migrations: List<AbstractMigration>, dbConfig: DbConfig, migrationTableName: String = "harmonica_migration") {
    val connection = Connection(dbConfig)
    
    val versionService = VersionService(migrationTableName)
    
    try {
        connection.transaction {
            versionService.setupHarmonicaMigrationTable(connection)
        }
        for (migration in migrations) {
            val migrationVersion =
                versionService.pickUpVersionFromClassName(migration.javaClass.name)
            if (versionService.isVersionMigrated(connection, migrationVersion)) continue

            connection.transaction {
                migration.connection = connection
                migration.up()
                versionService.saveVersion(connection, migrationVersion)
            }
        }
        connection.close()
    } catch (e: Exception) {
        connection.close()
        throw e
    }
}

You can’t implement it externally, because everything on the VersionService and AbstractMigration.connection is internal, but it should work if added inside the library.