如果仅添加新表，则进行反应式android数据库迁移

Question

我为数据库添加了新的命令，在使用ReActive android数据库运行程序时遇到此错误。

无法创建应用程序com.reactiveandroid.sample.App：java.lang.IllegalArgumentException：找到SQL文件资产/from_2_to_3.sql注释。

@Database(name = "AppDatabase", version = 3)
public class AppDatabase {
    static final Migration MIGRATION_1_2=new Migration(1,2) {
        @Override
        public void migrate(SQLiteDatabase database) {
            AssetsSqlMigration.executeSqlScript(database,"assets/from_1_to_2.sql");
        }
    };

    static final Migration MIGRATION_2_3=new Migration(2,3) {
        @Override
        public void migrate(SQLiteDatabase database) {
            AssetsSqlMigration.executeSqlScript(database,"assets/from_2_to_3.sql");
        }
    };
}

---

公共类应用程序扩展了应用程序{

@Override
public void onCreate() {
    super.onCreate();

    DatabaseConfig appDatabaseConfig = new DatabaseConfig.Builder(AppDatabase.class)
            .addModelClasses(Note.class, Folder.class, NoteFolderRelation.class)
            .addMigrations(AppDatabase.MIGRATION_1_2 ,MIGRATION_2_3)
            .disableMigrationsChecking()
            .build();

    ReActiveAndroid.init(new ReActiveConfig.Builder(this)
            .addDatabaseConfigs(appDatabaseConfig)
            .build());


}

}

---

ALTER TABLE注意添加列nameid INTEGER;

Answer 1

您需要按照以下说明在migrate()中编写DDL查询。

static final Migration MIGRATION_2_3 = new Migration(2, 3) {
    @Override
    public void migrate(SupportSQLiteDatabase database) {
        // if you need to create new table
        database.execSQL("ALTER TABLE your_table "
            + " ADD COLUMN column_name DATATYPE");
    }
};