如何在INSERT的另一列的值中使用表列的動態值

Question

我正在做類似下面的事情。

INSERT INTO example_table
            (start_time,
             start_time_type,
             end_time,
             end_time_type,
             duration)
SELECT IF(start_time_type = 'now'
           OR start_time < " . CURRENT_TIME . ", " . CURRENT_TIME . ",
       start_time),
       start_time_type,
       IF(list_in = 'store', 0, ( IF(end_time_type = 'duration',
                                  " . CURRENT_TIME . " + duration * 86400,
                                  end_time
                                  ) )),
       IF(list_in = 'store', '', 'duration'),
       IF(list_in = 'store', end_time - start_time / 86400, duration)
FROM   bulk_listings
WHERE  .....

現在，如您所見，在持續時間內，我想處理start_time和end_time的結果值； 但是顯然下面的代碼將不起作用，因為它將對我假設的列的當前值起作用，並且不會使用我想要的結果值 。

有什么辦法可以做我想要的嗎？

Answer 1

您需要使用您的計算值列創建一個子查詢：

SELECT start_time, start_time_type, end_time,
       IF(list_in = 'store', '', 'duration'),
       IF(list_in = 'store', end_time - start_time / 86400, duration)
FROM (SELECT IF(start_time_type = 'now'
           OR start_time < " . CURRENT_TIME . ", " . CURRENT_TIME . ",
       start_time) AS start_time,
       start_time_type,
       IF(list_in = 'store', 0, ( IF(end_time_type = 'duration',
                                  " . CURRENT_TIME . " + duration * 86400,
                                  end_time
                                  ) )) AS end_time,
       duration,
       list_in
FROM   bulk_listings
WHERE ...) AS SUBQUERY