Java Code Examples for com.j256.ormlite.stmt.QueryBuilder#queryForFirst()

/**
 * 返回最高得分
 * 
 * @return
 */
public GameRanking getTopScore()
{
	QueryBuilder<GameRanking, ?> qb = getDao().queryBuilder();
	try
	{
		// qb.where().eq("user_name", userName);
		qb.orderBy("score", false);
		return qb.queryForFirst();
	}
	catch (SQLException e)
	{
		e.printStackTrace();
	}

	return null;
}
 

public User getUserById(int userId) {
    try {
        QueryBuilder<User, Integer> qb = dao.queryBuilder();
        qb.where().eq(User.FIELD_NAME_ID, userId);
        return qb.queryForFirst();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return null;
}
 

/**
 * 通过表列名查询第一条记录
 *
 * @param map
 * @return
 */
public T queryForFirst(Map<String, Object> map) throws SQLException {
    QueryBuilder<T, Integer> queryBuilder = ormLiteDao.queryBuilder();
    Where where = queryBuilder.where();
    where.isNotNull("id");
    for (Map.Entry<String, Object> entry : map.entrySet()) {
        where.and().eq(entry.getKey(), entry.getValue());
    }
    return queryBuilder.queryForFirst();
}
 

/**
 * 排序查询
 *
 * @param map         查询条件键值组合
 * @param orderColumn 排序的列
 * @param ascending   是否升序
 * @return
 */
public T queryForFirstByOrder(Map<String, Object> map, String orderColumn, boolean ascending) throws SQLException {
    QueryBuilder<T, Integer> queryBuilder = ormLiteDao.queryBuilder();
    Where where = queryBuilder.where();
    queryBuilder.orderBy(orderColumn, ascending);
    where.isNotNull("id");
    for (Map.Entry<String, Object> entry : map.entrySet()) {
        where.and().eq(entry.getKey(), entry.getValue());
    }
    return queryBuilder.queryForFirst();
}
 

private void selectPointer() {
    if (filter != null) {
        Where<Message, Object> filteredWhere;
        try {
            filteredWhere = filter.modWhere(app.getDao(Message.class)
                    .queryBuilder().where());

            filteredWhere.and().le(Message.ID_FIELD, app.getPointer());

            QueryBuilder<Message, Object> closestQuery = app.getDao(
                    Message.class).queryBuilder();

            closestQuery.orderBy(Message.TIMESTAMP_FIELD, false).setWhere(
                    filteredWhere);
            Message closestMessage = closestQuery.queryForFirst();

            // use anchor message id if message was narrowed
            if (anchorId != -1) {
                selectMessage(getMessageById(anchorId));
            } else {
                recyclerView.scrollToPosition(adapter.getItemIndex(closestMessage));
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    } else {
        int anc = app.getPointer();
        selectMessage(getMessageById(anc));
    }
}
 

public Video getVideoForFilename(String path) {
	if (path == null) return null;
	
	String youtubeId = OfflineVideoManager.youtubeIdFromFilename(path);
	QueryBuilder<Video, String> q = videoDao.queryBuilder();
	try {
		q.where().eq("youtube_id", youtubeId);
		return q.queryForFirst();
	} catch (SQLException e) {
		e.printStackTrace();
		return null;
	}
}
 

@Test
public void testCacheWithSelectColumns() throws Exception {
	Dao<CacheWithSelectColumns, Object> dao = createDao(CacheWithSelectColumns.class, true);
	// Add object to database
	CacheWithSelectColumns foo = new CacheWithSelectColumns();
	foo.text = "some text";
	dao.create(foo);
	// enable object cache
	dao.setObjectCache(true);

	// fetch the object, but only with its id field
	QueryBuilder<CacheWithSelectColumns, Object> qb =
			dao.queryBuilder().selectColumns(CacheWithSelectColumns.COLUMN_NAME_ID);
	CacheWithSelectColumns result = qb.queryForFirst();
	assertNotNull(result);
	assertNull(result.text);

	// fetch the same object again, this time asking for the text column as well
	qb = dao.queryBuilder().selectColumns(CacheWithSelectColumns.COLUMN_NAME_ID,
			CacheWithSelectColumns.COLUMN_NAME_TEXT);
	result = qb.queryForFirst();
	assertNotNull(result);
	assertEquals(foo.text, result.text);

	// fetch the same object again, this time asking for everything
	qb = dao.queryBuilder();
	result = qb.queryForFirst();
	assertNotNull(result);
	assertEquals(foo.text, result.text);
}
 

/**
 * 排序查询
 *
 * @param columnName  查询条件列名
 * @param value       查询条件值
 * @param orderColumn 排序的列
 * @param ascending   是否升序
 * @return
 */
public T queryForFirstByOrder(String columnName, Object value, String orderColumn, boolean ascending) throws SQLException {
    QueryBuilder<T, Integer> queryBuilder = ormLiteDao.queryBuilder();
    queryBuilder.orderBy(orderColumn, ascending);
    queryBuilder.where().eq(columnName, value);
    return queryBuilder.queryForFirst();
}
 

/**
 * 按条件查询，返回第一条符号要求的记录
 *
 * @param columnName 查询条件列名
 * @param value      查询条件值
 * @return
 */
public T queryForFirst(String columnName, Object value) throws SQLException {
    QueryBuilder<T, Integer> queryBuilder = ormLiteDao.queryBuilder();
    queryBuilder.where().eq(columnName, value);
    return queryBuilder.queryForFirst();
}