如何根據數據條件在mysql中填充列？

Question

我在mysql表中有以下格式的數據

id   order_id    state     time_stamp
1       1       created    1:15 6/2/2015
2       2       created    1:17 6/2/2015
3       1         ack      1:18 6/2/2015
4       1       shipped    1:20 6/2/2015
5       1      delivered   1:25 6/2/2015
6       2         ack      1:25 6/2/2015 
7       2       shipped    1:26 6/2/2015
8       2      delivered   1:29 6/2/2015

我想查詢該數據庫以獲得以下格式的結果-

order_id     created_ts       ack_ts         shipped_ts      delivered_ts
 1         1:15 6/2/2015    1:18 6/2/2015   1:20 6/2/2015   1:25 6/2/2015
 2         1:17 6/2/2015    1:25 6/2/2015   1:26 6/2/2015   1:29 6/2/2015

是否可以將其編寫為選擇SQL查詢？ 請幫助進行示例查詢。 提前致謝。

Answer 1

也許是這樣的：

SELECT
    order_id,
    MAX(CASE WHEN state='created' THEN time_stamp ELSE NULL END) AS created_ts,
    MAX(CASE WHEN state='ack' THEN time_stamp ELSE NULL END) AS ack_ts,
    MAX(CASE WHEN state='shipped' THEN time_stamp ELSE NULL END) AS shipped_ts,
    MAX(CASE WHEN state='delivered' THEN time_stamp ELSE NULL END) AS delivered_ts
FROM
    Table1
GROUP BY
    order_id