我建议我们逐步增量地构建查询。验证每一步的查询结果是否符合我们的预期。当某些事情“不起作用”时,后退一步。
我们想要返回三行,每一行对应___Segmentations
,对于特定的hotelid
SELECT r.seg_id
, r.seg_text
FROM ___Segmentations r
WHERE r.seg_hotelid = :hotel_id
ORDER BY r.seg_id
将外连接添加到__Bookings
SELECT r.seg_id
, r.seg_text
, b.boo_id
FROM ___Segmentations r
LEFT
JOIN ___Bookings b
ON b.boo_segmentation = r.seg_id
WHERE r.seg_hotelid = :hotel_id
ORDER
BY r.seg_id
, b.boo_id
将外连接添加到___BillableDatas
SELECT r.seg_id
, r.seg_text
, b.boo_id
, d.bil_id
FROM ___Segmentations r
LEFT
JOIN ___Bookings b
ON b.boo_segmentation = r.seg_id
LEFT
JOIN `___BillableDatas` d
ON d.bil_bookingid = b.boo_id
WHERE r.seg_hotelid = :hotel_id
ORDER
BY r.seg_id
, b.boo_id
, d.bil_id
如果这是我们感兴趣的行,我们可以进行聚合。
SELECT r.seg_id
, r.seg_text
, COUNT(DISTINCT b.boo_id) AS cnt_bookings
, COUNT(DISTINCT d.bil_id) AS cnt_billable
FROM ___Segmentations r
LEFT
JOIN ___Bookings b
ON b.boo_segmentation = r.seg_id
LEFT
JOIN `___BillableDatas` d
ON d.bil_bookingid = b.boo_id
WHERE r.seg_hotelid = :hotel_id
GROUP
BY r.seg_id
, r.seg_text
ORDER
BY r.seg_text
现在获取“总计”的聚合。
我将采取的方法是使用 CROSS JOIN 操作来制作行的“副本”。我们可以连接我们编写的第一个查询返回的行,作为内联视图引用。 (别名为q
以下。)
如果我们有一组完整的行,对每个行重复seg_id/seg_text
(我们编写的第一个查询),我们可以使用条件聚合。
我们编写的最后一个查询(就在上面)是下面查询中的内联视图,别名为c
.
SUM of cnt_bookings
所有行就是总数。
对于单个计数,我们可以仅包含具有匹配的行seg_id
,该子集的总数。
SELECT q.seg_id
, q.seg_text
, SUM(IF(c.seg_id=q.seg_id,c.cnt_bookings,0)) AS cnt_bookings
, SUM(c.cnt_bookings) AS tot_bookings
, SUM(IF(c.seg_id=q.seg_id,c.cnt_billable,0)) AS cnt_billable
, SUM(c.cnt_billable) AS tot_billable
FROM ( SELECT t.seg_id
, t.seg_text
FROM ___Segmentations t
WHERE t.seg_hotelid = :hotel_id_1
ORDER BY t.seg_id
) q
CROSS
JOIN ( SELECT r.seg_id
, COUNT(DISTINCT b.boo_id) AS cnt_bookings
, COUNT(DISTINCT d.bil_id) AS cnt_billable
FROM ___Segmentations r
LEFT
JOIN ___Bookings b
ON b.boo_segmentation = r.seg_id
LEFT
JOIN `___BillableDatas` d
ON d.bil_bookingid = b.boo_id
WHERE r.seg_hotelid = :hotel_id
GROUP
BY r.seg_id
) c
GROUP
BY q.seg_id
, q.seg_text
ORDER
BY q.seg_text
In the SELECT
列表,我们可以进行除法以获得百分比:cnt_bookings * 100.0 / tot_bookings
e.g.
SELECT q.seg_id
, q.seg_text
, SUM(IF(c.seg_id=q.seg_id,c.cnt_bookings,0)) AS cnt_bookings
, SUM(c.cnt_bookings) AS tot_bookings
, SUM(IF(c.seg_id=q.seg_id,c.cnt_bookings,0))
* 100.0 / SUM(c.cnt_bookings) AS pct_bookings
, SUM(IF(c.seg_id=q.seg_id,c.cnt_billable,0)) AS cnt_billable
, SUM(c.cnt_billable) AS tot_billable
, SUM(IF(c.seg_id=q.seg_id,c.cnt_billable,0))
* 100.0 / SUM(c.cnt_billable) AS pct_billable
修改 ORDER BY 子句以按所需顺序返回行
从SELECT
列出返回的表达式tot_bookings
and tot_billable
.
EDIT
我想我错过了日期标准。我们可以将外连接变成内连接,并将CROSS JOIN替换为LEFT JOIN。我们有可能返回 NULL 值cnt_bookings
and cnt_billable
,我们可以将它们包装在 IFNULL() 或 COALESCE() 函数中,以将 NULL 替换为零。
SELECT q.seg_id
, q.seg_text
, SUM(IF(c.seg_id=q.seg_id,c.cnt_bookings,0)) AS cnt_bookings
, SUM(c.cnt_bookings) AS tot_bookings
, SUM(IF(c.seg_id=q.seg_id,c.cnt_bookings,0))
* 100.0 / SUM(c.cnt_bookings) AS pct_bookings
, SUM(IF(c.seg_id=q.seg_id,c.cnt_billable,0)) AS cnt_billable
, SUM(c.cnt_billable) AS tot_billable
, SUM(IF(c.seg_id=q.seg_id,c.cnt_billable,0))
* 100.0 / SUM(c.cnt_billable) AS pct_billable
FROM ( SELECT t.seg_id
, t.seg_text
FROM ___Segmentations t
WHERE t.seg_hotelid = :hotel_id_1
ORDER BY t.seg_id
) q
LEFT
JOIN ( SELECT r.seg_id
, COUNT(DISTINCT b.boo_id) AS cnt_bookings
, COUNT(DISTINCT d.bil_id) AS cnt_billable
FROM ___Segmentations r
JOIN ___Bookings b
ON b.boo_segmentation = r.seg_id
JOIN `___BillableDatas` d
ON d.bil_bookingid = b.boo_id
AND d.bil_date BETWEEN '2017-02-21' AND '2017-02-28'
WHERE r.seg_hotelid = :hotel_id
GROUP
BY r.seg_id
) c
ON 1=1
GROUP
BY q.seg_id
, q.seg_text
ORDER
BY q.seg_text