SQL按日期降序表达式

Question

我有2个表，Worker和Worker_Balance：

---------------           ------------------
|  Worker     |           | Worker_Balance |
|-------------|<----------|----------------|
|             |           | INT workerBID  |
| ...         |           | INT amount     |
---------------           | INT workerID   |
                          | DATE timestamp |
                          ------------------

以及以下sql-query：

SELECT Worker.ID, Worker.xy, SUM(Worker_Balance.amount)
FROM Worker
JOIN Worker_Balance ON WorkerBalance.workerID = Worker.workerID
GROUP BY Worker.ID, Worker.xy

我需要按最新时间戳排序的结果，但最旧的必须是第一个。因此，最后一笔交易最早的工人是第一位。

Answer 1

您需要GROUP BY才能汇总和ORDER BY才能进行排序：

SELECT Worker.ID
    ,Worker.xy
    ,MAX(Worker.TIMESTAMP) last_transaction
    ,SUM(Worker_Balance.amount)
FROM Worker
JOIN Worker_Balance ON WorkerBalance.workerID = Worker.workerID
GROUP BY Worker.ID
    ,Worker.xy
ORDER BY last_transaction