AndroidでORM「ormlite」を使う

AndroidでもORMを使いたいなーと思って探してみたら、ormliteというのがあった！

OrmLite - Lightweight Object Relational Mapping (ORM) Java Package

ということで、AndroidStudioで使うときの備忘録。

build.gradleに追加

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.j256.ormlite:ormlite-core:4.23'
    compile 'com.j256.ormlite:ormlite-android:4.48'
}

Entityクラス

サンプルはこんな感じ。

@DatabaseTable(tableName = BookEntity.TABLE_NAME)
public class BookEntity {
    public static final String TABLE_NAME = "book";
    public static final String BOOK_ID = "book_id";
    public static final String BOOK_TITLE = "book_title";
    public static final String BOOK_AUTHOR = "book_author";

    @DatabaseField(generatedId = true, columnName = BOOK_ID)
    private Long bookId;
    @DatabaseField(columnName = BOOK_ISBN)
    private String bookTitle;
    @DatabaseField(columnName = BOOK_AUTHOR, defaultValue = "")
    private String bookAuthor;
}

DBHelperクラス

public class DBHelper extends OrmLiteSqliteOpenHelper {
    protected final static Integer DB_VERSION = 2;
    protected final static String DB_NAME = "mydatabase.db";

    public DBHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    public DBHelper(Context context, int dbVersion) {
        super(context, DB_NAME, null, dbVersion);
    }

    @Override
    public void onCreate(SQLiteDatabase db, ConnectionSource connectionSource) {
        try {
            TableUtils.createTable(connectionSource, BookEntity.class);
        } catch (SQLException e) {
            Log.e(DBHelper.class.getName(), "データベースを作成できませんでした", e);
        }
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource, int oldVersion, int newVersion) {
        Dao<BookEntity, Integer> dao = null;
        try {
            dao = getDao(BookEntity.class);
            if (oldVersion < 2) {
                // we added the age column in version 2
                dao.executeRaw("ALTER TABLE `" + BookDto.TABLE_NAME + "` ADD COLUMN " + BookDto.BOOK_WATCH + " Integer DEFAULT 0;");
            }
        } catch (SQLException e) {
            Log.e(DBHelper.class.getName(), "データベースを更新できませんでした", e);
        }

    }

Daoクラス

SELECT

// Daoの生成
DBHelper helper = new DBHelper(context);
Dao<BookEntity, Integer> dao = helper.getDao(BookEntity.class);

//全レコード取得
List<BookEntity> result_list =  dao.queryForAll();

//1件取得
BookEntity result =  dao.queryBuilder()
                    .where()
                    .eq(BookEntity.BOOK_ID, 1)
                    .queryForFirst();

//複数件取得
List<BookEntity> result_list =  dao.queryBuilder()
                    .orderBy(BookEntity.BOOK_AUTHOR, true)
                    .orderBy(BookEntity.BOOK_TITLE, true)
                    .where()
                    .like(BookEntity.BOOK_AUTHOR, "Joe %")
                    .query();

//ページング
int PAGING_LIMIT = 20;
int page = 1;
List<BookEntity> result_list = dao.queryBuilder()
                    .offset((page - 1) * PAGING_LIMIT)
                    .limit(PAGING_LIMIT)
                    .query();

INSERT, UPDATE

DBHelper helper = new DBHelper(context);
Dao<BookEntity, Integer> dao = helper.getDao(BookEntity.class);

//INSERT
BookEntity dto = ...;
int return_id = dao.create(dto);

//INSERT or UPDATE
int num_lines_changed = dao.createOrUpdate(dto).getNumLinesChanged();

DELETE

DBHelper helper = new DBHelper(context);
Dao<BookEntity, Integer> dao = helper.getDao(BookEntity.class);
DeleteBuilder<BookEntity, Integer> builder = dao.deleteBuilder();
builder.where().eq(BookEntity.BOOK_ID, 1);