02b-room-migrations

app/schemas/com.karumi.jetpack.superheroes.common.SuperHeroesDatabase/2.json

@@ -0,0 +1,58 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 2,
+    "identityHash": "4250c22060f75f31b611cfdc08f9177d",
+    "entities": [
+      {
+        "tableName": "superheroes",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`superhero_id` TEXT NOT NULL, `superhero_name` TEXT NOT NULL, `superhero_photo` TEXT, `superhero_isAvenger` INTEGER NOT NULL, `superhero_description` TEXT NOT NULL, PRIMARY KEY(`superhero_id`))",
+        "fields": [
+          {
+            "fieldPath": "superHero.id",
+            "columnName": "superhero_id",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "superHero.name",
+            "columnName": "superhero_name",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "superHero.photo",
+            "columnName": "superhero_photo",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "superHero.isAvenger",
+            "columnName": "superhero_isAvenger",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "superHero.description",
+            "columnName": "superhero_description",
+            "affinity": "TEXT",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "superhero_id"
+          ],
+          "autoGenerate": false
+        },
+        "indices": [],
+        "foreignKeys": []
+      }
+    ],
+    "views": [],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, \"4250c22060f75f31b611cfdc08f9177d\")"
+    ]
+  }
+}

app/src/androidTest/java/com/karumi/jetpack/superheroes/data/repository/room/MigrationTest.kt

@@ -0,0 +1,76 @@
+package com.karumi.jetpack.superheroes.data.repository.room
+
+import androidx.room.testing.MigrationTestHelper
+import androidx.sqlite.db.SupportSQLiteDatabase
+import androidx.sqlite.db.framework.FrameworkSQLiteOpenHelperFactory
+import androidx.test.platform.app.InstrumentationRegistry
+import com.karumi.jetpack.superheroes.common.Migrations
+import com.karumi.jetpack.superheroes.common.SuperHeroesDatabase
+import org.junit.Assert.assertEquals
+import org.junit.Rule
+import org.junit.Test
+
+class MigrationTest {
+    companion object {
+        private const val TEST_DB = "migration-test"
+        private const val SUPER_HERO_ID = "IronMan"
+        private const val SUPER_HERO_NAME = "Iron Man"
+        private val SUPER_HERO_URL: String? = null
+        private const val SUPER_HERO_IS_AVENGER = true
+        private const val SUPER_HER_DESCRIPTION = "Iron Man is a super hero"
+    }
+
+    @Rule
+    @JvmField
+    val helper: MigrationTestHelper = MigrationTestHelper(
+        InstrumentationRegistry.getInstrumentation(),
+        SuperHeroesDatabase::class.java.canonicalName,
+        FrameworkSQLiteOpenHelperFactory()
+    )
+
+    @Test
+    fun migrate1To2() = withDb(
+        fromVersion = 1,
+        toVersion = 2,
+        given = { insertSuperHeroInVersion1() },
+        then = { assertSuperHeroExistsInVersion2() }
+    )
+
+    private fun withDb(
+        fromVersion: Int,
+        toVersion: Int,
+        given: SupportSQLiteDatabase.() -> Unit,
+        then: SupportSQLiteDatabase.() -> Unit
+    ) {
+        val db = helper.createDatabase(TEST_DB, fromVersion)
+        given(db)
+        helper.runMigrationsAndValidate(TEST_DB, toVersion, true, *Migrations.all)
+        then(db)
+        helper.closeWhenFinished(db)
+    }
+
+    private fun SupportSQLiteDatabase.assertSuperHeroExistsInVersion2() {
+        val cursor = query("SELECT * FROM superheroes")
+        cursor.moveToFirst()
+        assertEquals(SUPER_HERO_ID, cursor.getString(0))
+        assertEquals(SUPER_HERO_NAME, cursor.getString(1))
+        assertEquals(SUPER_HERO_URL, cursor.getString(2))
+        assertEquals(SUPER_HERO_IS_AVENGER.toInt(), cursor.getInt(3))
+        assertEquals(SUPER_HER_DESCRIPTION, cursor.getString(4))
+    }
+
+    private fun SupportSQLiteDatabase.insertSuperHeroInVersion1() {
+        execSQL(
+            """
+                INSERT INTO superheroes VALUES(
+                    "$SUPER_HERO_ID",
+                    "$SUPER_HERO_NAME",
+                    $SUPER_HERO_URL,
+                    ${SUPER_HERO_IS_AVENGER.toInt()},
+                    "$SUPER_HER_DESCRIPTION"
+                )"""
+        )
+    }
+}
+
+private fun Boolean.toInt() = if (this) 1 else 0

app/src/main/java/com/karumi/jetpack/superheroes/SuperHeroesApplication.kt

@@ -1,7 +1,6 @@
 package com.karumi.jetpack.superheroes
 
 import android.app.Application
-import androidx.room.Room
 import com.karumi.jetpack.superheroes.common.SuperHeroesDatabase
 import com.karumi.jetpack.superheroes.common.module
 import com.karumi.jetpack.superheroes.data.repository.LocalSuperHeroDataSource
@@ -35,12 +34,7 @@ class SuperHeroesApplication : Application(), KodeinAware {
 
     private fun appDependencies(): Kodein.Module = module {
         bind<SuperHeroesDatabase>() with singleton {
-            Room.databaseBuilder(
-                this@SuperHeroesApplication,
-                SuperHeroesDatabase::class.java,
-                "superheroes-db"
-            ).fallbackToDestructiveMigration()
-                .build()
+            SuperHeroesDatabase.build(this@SuperHeroesApplication)
         }
         bind<SuperHeroDao>() with provider {
             val database: SuperHeroesDatabase = instance()

app/src/main/java/com/karumi/jetpack/superheroes/common/SuperHeroesDatabase.kt

@@ -1,11 +1,62 @@
 package com.karumi.jetpack.superheroes.common
 
+import android.content.Context
 import androidx.room.Database
+import androidx.room.Room
 import androidx.room.RoomDatabase
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
 import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroDao
 import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroEntity
 
-@Database(entities = [SuperHeroEntity::class], version = 1)
+@Database(entities = [SuperHeroEntity::class], version = SuperHeroesDatabase.version)
 abstract class SuperHeroesDatabase : RoomDatabase() {
     abstract fun superHeroesDao(): SuperHeroDao
+
+    companion object {
+        const val version = 2
+        fun build(context: Context): SuperHeroesDatabase =
+            Room.databaseBuilder(context, SuperHeroesDatabase::class.java, "superheroes-db")
+                .addMigrations(*Migrations.all)
+                .build()
+    }
+}
+
+object Migrations {
+    val from1To2 = object : Migration(1, 2) {
+        override fun migrate(database: SupportSQLiteDatabase) {
+            database.execSQL(
+                """
+            CREATE TABLE `superheroes_temp` (
+                `superhero_id` TEXT NOT NULL,
+                `superhero_name` TEXT NOT NULL,
+                `superhero_photo` TEXT,
+                `superhero_isAvenger` INTEGER NOT NULL DEFAULT 0,
+                `superhero_description` TEXT NOT NULL,
+                PRIMARY KEY(`superhero_id`)
+            )
+        """
+            )
+            database.execSQL(
+                """
+            INSERT INTO `superheroes_temp`(
+                `superhero_id`,
+                `superhero_name`,
+                `superhero_photo`,
+                `superhero_isAvenger`,
+                `superhero_description`
+            ) SELECT
+                `id`,
+                `name`,
+                `photo`,
+                `isAvenger`,
+                `description`
+            FROM `superheroes`"""
+            )
+            database.execSQL("DROP TABLE superheroes")
+            database.execSQL("ALTER TABLE `superheroes_temp` RENAME TO `superheroes`")
+        }
+    }
+
+    val all = arrayOf(from1To2)
 }

app/src/main/java/com/karumi/jetpack/superheroes/data/repository/LocalSuperHeroDataSource.kt

@@ -22,13 +22,11 @@ class LocalSuperHeroDataSource(
     }
 
     fun save(superHero: SuperHero): SuperHero {
-        executor.execute { dao.insertAll(listOf(superHero.toEntity())) }
+        executor.execute { dao.update(superHero.toEntity()) }
         return superHero
     }
 
-    private fun SuperHeroEntity.toSuperHero(): SuperHero =
-        SuperHero(id, name, photo, isAvenger, description)
+    private fun SuperHeroEntity.toSuperHero(): SuperHero = superHero
 
-    private fun SuperHero.toEntity(): SuperHeroEntity =
-        SuperHeroEntity(id, name, photo, isAvenger, description)
+    private fun SuperHero.toEntity(): SuperHeroEntity = SuperHeroEntity(this)
 }

app/src/main/java/com/karumi/jetpack/superheroes/data/repository/room/SuperHeroDao.kt

@@ -4,18 +4,22 @@ import androidx.room.Dao
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
 import androidx.room.Query
+import androidx.room.Update
 
 @Dao
 interface SuperHeroDao {
-    @Query("SELECT * FROM superheroes ORDER BY id ASC")
+    @Query("SELECT * FROM superheroes ORDER BY superhero_id ASC")
     fun getAll(): List<SuperHeroEntity>
 
-    @Query("SELECT * FROM superheroes WHERE id = :id")
+    @Query("SELECT * FROM superheroes WHERE superhero_id = :id")
     fun getById(id: String): SuperHeroEntity?
 
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     fun insertAll(superHeroes: List<SuperHeroEntity>)
 
+    @Update
+    fun update(superHero: SuperHeroEntity)
+
     @Query("DELETE FROM superheroes")
     fun deleteAll()
 }

app/src/main/java/com/karumi/jetpack/superheroes/data/repository/room/SuperHeroEntity.kt

@@ -1,13 +1,10 @@
 package com.karumi.jetpack.superheroes.data.repository.room
 
+import androidx.room.Embedded
 import androidx.room.Entity
-import androidx.room.PrimaryKey
+import com.karumi.jetpack.superheroes.domain.model.SuperHero
 
-@Entity(tableName = "superheroes")
+@Entity(tableName = "superheroes", primaryKeys = ["superhero_id"])
 data class SuperHeroEntity(
-    @PrimaryKey val id: String,
-    val name: String,
-    val photo: String?,
-    val isAvenger: Boolean,
-    val description: String
+    @Embedded(prefix = "superhero_") val superHero: SuperHero
 )