私は次のクエリで次の結果持って

Question

、GROUP BYで列にNULLでない値を持つレジスタを選択します。私はnullではないid_taskでレジスタを取得しようとしている

SELECT `id_booking`, `id_task`, `type`, `date` 
FROM (SELECT `id` AS `id_booking`, null AS `id_task`, 1 AS `type`, `date_in` AS `date` 
    FROM `booking` 
    WHERE `date_in` <= '2016-10-24' 
    AND `date_in` >= '2016-10-14' 
    AND `status` = 'accepted' 
    UNION ALL 
    SELECT `id` AS `id_booking`, null AS `id_task`, 2 AS `type`, `date_out` AS `date` 
    FROM `booking` 
    WHERE `date_out` <= '2016-10-24' 
    AND `date_out` >= '2016-10-14' 
    AND `status` = 'accepted' 
    UNION ALL 
    SELECT `booking_id` AS `id_booking`, `id` AS `id_task`, `id_type` AS `type`, `date` AS `date` 
    FROM `task` 
    WHERE `date` <= '2016-10-24' 
    AND `date` >= '2016-10-14') 
    AS `tasks` 
ORDER BY `date` ASC 

をid_bookingとtypeが重複していますが、私がGROUP BY節を導入した場合は、id_task = NULLの最初の1つのレジスタを取得できます。

GROUP BYでグループ化された複数のレジスタ間でnull以外の値を持つレジスタを取る可能性はありますか？

Answer 1

少し複雑...

いますが、唯一のid聖霊降臨祭は、行を複製してこれらのみではないとヌルタイプ

SELECT `id_booking`, `id_task`, `type`, `date` 
    FROM (SELECT `id` AS `id_booking`, null AS `id_task`, 1 AS `type`, `date_in` AS `date` 
     FROM `booking` 
     WHERE `date_in` <= '2016-10-24' 
     AND `date_in` >= '2016-10-14' 
     AND `status` = 'accepted' 
     UNION ALL 
     SELECT `id` AS `id_booking`, null AS `id_task`, 2 AS `type`, `date_out` AS `date` 
     FROM `booking` 
     WHERE `date_out` <= '2016-10-24' 
     AND `date_out` >= '2016-10-14' 
     AND `status` = 'accepted' 
     UNION ALL 
     SELECT `booking_id` AS `id_booking`, `id` AS `id_task`, `id_type` AS `type`, `date` AS `date` 
     FROM `task` 
     WHERE `date` <= '2016-10-24' 
     AND `date` >= '2016-10-14') AS `tasks` 
    where (`id_booking`, `type`) in ( select `id_booking`, `type` FROM 
      (SELECT `id` AS `id_booking`, null AS `id_task`, 1 AS `type`, `date_in` AS `date` 
       FROM `booking` 
       WHERE `date_in` <= '2016-10-24' 
       AND `date_in` >= '2016-10-14' 
       AND `status` = 'accepted' 
       UNION ALL 
       SELECT `id` AS `id_booking`, null AS `id_task`, 2 AS `type`, `date_out` AS `date` 
       FROM `booking` 
       WHERE `date_out` <= '2016-10-24' 
       AND `date_out` >= '2016-10-14' 
       AND `status` = 'accepted' 
       UNION ALL 
       SELECT `booking_id` AS `id_booking`, `id` AS `id_task`, `id_type` AS `type`, `date` AS `date` 
       FROM `task` 
       WHERE `date` <= '2016-10-24' 
       AND `date` >= '2016-10-14') t 
       group by `id_booking`, `type` 
       having count(*) > 1   
    ) 
    and id_task is not null 

union 

SELECT `id_booking`, `id_task`, `type`, `date` 
    FROM (SELECT `id` AS `id_booking`, null AS `id_task`, 1 AS `type`, `date_in` AS `date` 
     FROM `booking` 
     WHERE `date_in` <= '2016-10-24' 
     AND `date_in` >= '2016-10-14' 
     AND `status` = 'accepted' 
     UNION ALL 
     SELECT `id` AS `id_booking`, null AS `id_task`, 2 AS `type`, `date_out` AS `date` 
     FROM `booking` 
     WHERE `date_out` <= '2016-10-24' 
     AND `date_out` >= '2016-10-14' 
     AND `status` = 'accepted' 
     UNION ALL 
     SELECT `booking_id` AS `id_booking`, `id` AS `id_task`, `id_type` AS `type`, `date` AS `date` 
     FROM `task` 
     WHERE `date` <= '2016-10-24' 
     AND `date` >= '2016-10-14') AS `tasks` 
    where (`id_booking`, `type`) in ( select `id_booking`, `type` FROM 
      (SELECT `id` AS `id_booking`, null AS `id_task`, 1 AS `type`, `date_in` AS `date` 
       FROM `booking` 
       WHERE `date_in` <= '2016-10-24' 
       AND `date_in` >= '2016-10-14' 
       AND `status` = 'accepted' 
       UNION ALL 
       SELECT `id` AS `id_booking`, null AS `id_task`, 2 AS `type`, `date_out` AS `date` 
       FROM `booking` 
       WHERE `date_out` <= '2016-10-24' 
       AND `date_out` >= '2016-10-14' 
       AND `status` = 'accepted' 
       UNION ALL 
       SELECT `booking_id` AS `id_booking`, `id` AS `id_task`, `id_type` AS `type`, `date` AS `date` 
       FROM `task` 
       WHERE `date` <= '2016-10-24' 
       AND `date` >= '2016-10-14') t 
       group by `id_booking`, `type` 
       having count(*) = 1   
    ) 
    and id_task is null 

ORDER BY `date` ASC