次の値を含めることができるORDERBYで終わるloooooooooooongSELECTがあります。
- チェック済み(1または0)
- 日付(YYYY-MM-DD)
- 時間(HH:MM:SS)
クエリの結果を次のように並べ替えたいと思います。
|__checked = 0
| |__ date ASC
| |__ time ASC
| |__ date && time are null
|__checked = 1
|__ date ASC
|__ time ASC
|__ date && time are null
今のところ、「ORDER BY i1.checked、date、time」のような単純なものを取得しましたが、問題は、日付と時刻が空のアイテムが一番上に残ることです。
適切な解決策を見つけるためにすべてのデータが必要だと思った場合のクエリ全体を次に示します。悲鳴を上げないでください。
SELECT i1._id AS _id, i1.title AS title, i1.checked AS checked,
// count the children (-1 is because the closure table include a relation between any item and itself)
(count( c1.item_id ) - 1) AS children_count,
// count the unchecked children
(SELECT (COUNT(DISTINCT i2._id) )
FROM item AS i2 JOIN closure AS c2 ON (i2._id = c2.item_id)
WHERE c2.ancestor_id = i1._id
AND i2.checked = 0
AND c2.item_id NOT IN (0, i1._id)) AS unchecked_children_count,
// get the closest deadlines among the children :
// if there is a date but no time, time is set to 00:00:00
// if there is a time but not date, date is set to today
// if there is no date nor time, both are set to an empty string
// date
ifnull(nullif((SELECT ifnull(nullif(i3.date, ""), date()) AS subdate
FROM item AS i3 JOIN closure AS c3 ON (i3._id = c3.item_id)
WHERE c3.ancestor_id = i1._id
AND (i3.date OR i3.time)
ORDER By subdate, ifnull(nullif(i3.time, ""), "00:00:00")
LIMIT 1), ""), "") AS date,
// time
ifnull(nullif((SELECT ifnull(nullif(i4.time, ""), "00:00:00") AS subtime
FROM item AS i4 JOIN closure AS c4 ON (i4._id = c4.item_id)
WHERE c4.ancestor_id = i1._id
AND (i4.date OR i4.time)
ORDER By ifnull(nullif(i4.date, ""), date()), subtime
LIMIT 1), ""), "") AS time
FROM item AS i1 JOIN closure AS c1 ON ( i1._id = c1.ancestor_id )
WHERE i1.parent_id = 0
AND c1.item_id != 0
GROUP BY c1.ancestor_id
ORDER BY i1.checked, date, time
アイテムは、parent_idとクロージャーテーブルを持つツリーに編成されています。