android-data

Android Data Layer Reference

A skill distilled from the official Android app development (Kotlin) data layer documentation. Depending on the user's task, read the appropriate README.md and follow it to the individual files.

Directory structure

skills/android-data/
  SKILL.md
  references/
    room/
      README.md
      entity.md
      primary-key.md
      column-info.md
      ignore.md
      embedded.md
      foreign-key.md
      dao.md
      query.md
      insert.md
      update.md
      delete.md
      upsert.md
      transaction.md
      database.md
      room-database-builder.md
      callback-driver.md
      migration.md
      type-converter.md
      relation.md
      fts-database-view.md
      async-queries.md
      testing.md
    datastore/
      README.md
      datastore.md
      datastore-factory.md
      preferences-datastore.md
      preferences.md
      preferences-keys.md
      edit.md
      proto-datastore.md
      data-migration.md
      shared-preferences-migration.md
      corruption-handler.md
    files-storage/
      README.md
      storage-overview.md
      app-specific-storage.md
      internal-file-io.md
      shared-preferences.md
      auto-backup.md
      mediastore.md
      storage-access-framework.md
      photo-picker.md
      embedded-photo-picker.md
      file-provider.md
      uri-permissions.md
      blobstore-manager.md
      scoped-storage.md
      cache-management.md
      activity-result-contracts-files.md
      assets.md
    network/
      README.md
      permissions-and-threading.md
      network-security-config.md
      connectivitymanager.md
      networkcapabilities.md
      network-callback.md
      data-saver.md
      downloadmanager.md
      cronet.md
      cronet-urlrequest.md
      cronet-okhttp-interceptor.md
      retrofit.md
      okhttp.md
      okhttp-websocket.md
      kotlinx-serialization-converter.md
      httpurlconnection.md
      caching-and-retry.md

Exploration procedure

Derive the category from the task, and identify the target page in the category's README.md:

1. Find the category corresponding to the task in the mapping table below
2. of that category references/{category}/README.md Refer to to identify the target page
3. Read the .md of the relevant page to check the details

Task → Category Mapping

Task	Category	Reference README
Want to define Entity / Dao / Database with Room	room	references/room/README.md
Want to write SQL operations with @Query / @Insert / @Update / @Delete / @Upsert	room	references/room/README.md
Want to change the schema with Room's Migration / AutoMigration	room	references/room/README.md
Want to handle related data and full-text search with @Relation / @Fts4 / @DatabaseView	room	references/room/README.md
Want to persist key-value and typed data with Preferences DataStore / Proto DataStore	datastore	references/datastore/README.md
Want to migrate from SharedPreferences to DataStore	datastore	references/datastore/README.md
Want to save and read files in internal/external storage	files-storage	references/files-storage/README.md
Want to handle media files with MediaStore / Storage Access Framework / Photo Picker	files-storage	references/files-storage/README.md
Want to share files with other apps with FileProvider	files-storage	references/files-storage/README.md
Want to check the constraints of scoped storage and MANAGE_EXTERNAL_STORAGE	files-storage	references/files-storage/README.md
Want to monitor network status with ConnectivityManager	network	references/network/README.md
Want to configure communication policies with Network Security Config	network	references/network/README.md
Want to implement HTTP communication with Retrofit / OkHttp / Cronet	network	references/network/README.md

Paging 3 は android-architecture、WorkManager は android-background-work, runtime permissions are android-platform-core is in charge of.