Initialization

Create driver and repositories

Create one SqlDriver and pass it to each repository. All repositories share the same driver — SQLite is a single-file database and a single SqlDriver instance manages the connection.

TaskTrackerApp.kt

class TaskTrackerApp : Application() {

    lateinit var projectRepo: ProjectRepository
    lateinit var taskRepo: TaskRepository
    lateinit var checklistRepo: ChecklistItemRepository

    override fun onCreate() {
        super.onCreate()
        val driver = AndroidDatabaseDriverFactory(this).create("tasktracker.db")

        projectRepo   = ProjectRepository(driver).also  { it.createTable() }
        taskRepo      = TaskRepository(driver).also     { it.createTable() }
        checklistRepo = ChecklistItemRepository(driver).also { it.createTable() }
    }
}

Register in AndroidManifest.xml:

AndroidManifest.xml

<application
    android:name=".TaskTrackerApp"
    ...>

About createTable()

createTable() does two things every time it is called:

1. Runs CREATE TABLE IF NOT EXISTS — safe to call repeatedly; no-op if the table exists.
2. Runs SchemaMigrator.sync() — diffs the live schema against the generated column list and migrates if needed.

Call it on every launch. It is fast when the schema hasn't changed (just a PRAGMA table_info read) and performs the necessary migration when it has.

Call order matters for foreign key integrity

Call createTable() on the parent table before the child table if you are enforcing foreign key relationships manually. In this sample: projectRepo.createTable() before taskRepo.createTable().

Access from Activities and ViewModels

// From an Activity
val app = application as TaskTrackerApp
val taskRepo = app.taskRepo

// From a ViewModel (inject via factory or DI)
class ProjectViewModel(private val projectRepo: ProjectRepository) : ViewModel()

iOS (KMP)

On iOS, use IosDatabaseDriverFactory in place of the Android one:

iosMain

val driver = IosDatabaseDriverFactory().create("tasktracker.db")
val projectRepo = ProjectRepository(driver).also { it.createTable() }