我在困难的查询中需要帮助。这与优惠券在Spree Commerce平台中实施的复杂方式有关。
我只需要优惠券总额。
表格是：
偏好
id | value | key
---+---------------------------------------------
1 | 25 | spree/calculator/flat_rate/amount/5
计算器
id | calculable_id | calculable_type
----+---------------+-----------------
5 | 3 | promotion_action
promotion_actions
id | activator_id
----+-------------
3 | 2
的活化剂
id | expires_at | usage_limit
---+------------+------------
2 | 2013-12-01 | 4
调整
originator_type | originator_id | amount
-----------------+---------------+-------
promotion_action | 3 | -25
preferences.key中的最后一个数字对应于计算器的ID。
首先我需要prefers.amount的总数，乘以activators.usage_limit（除非activators.expires_at＆lt; today），其中preferences.key LIKE＆＃39;％calculator / flat_rate％＆＃39;。
结果应为此金额减去相应adjust.amount的总和
我到目前为止
select
(select sum(value) from spree_preferences
where `key` like "%calculator/flat_rate%")
+
(select sum(amount) from spree_adjustments
where originator_type = 'promotion_action') as total;
，但这并没有考虑到expires_at和usage_limit。
对于更新的狂欢，答案如下：
select sum(subAggregate.outstanding)
from
(
select (subDetail.value * subDetail.multiplier) + subDetail.adjustmentAmount as outstanding
from
(
select p.value,
case
when a.expires_at > curDate() then a.usage_limit
else 1
end as multiplier ,
ifNull(adj.amount,0) as adjustmentAmount
from spree_preferences p
left outer join spree_calculators c
on replace(p.key,'spree/calculator/flat_rate/amount/','') = c.id
left outer join spree_promotion_actions pa
on c.calculable_id = pa.id
and c.calculable_type = 'Spree::PromotionAction'
left outer join spree_promotions a
on pa.promotion_id = a.id
left outer join spree_adjustments adj
on pa.id = adj.source_id
and pa.type = 'Spree::PromotionAction'
) subDetail
) subAggregate
答案 0 :(得分：2)
select sum(subAggregate.outstanding)
from
(
select (subDetail.value * subDetail.multiplier) + subDetail.adjustmentAmount as outstanding
from
(
select p.value,
case
when a.expires_at > curDate() then a.usage_limit
else 1
end as multiplier ,
ifNull(adj.amount,0) as adjustmentAmount
from preferences p
left outer join calculators c
on replace(p.key,'spree/calculator/flat_rate/amount/','') = c.id
left outer join promotion_actions pa
on c.calculabel_id = pa.id
and c.calculable_type = 'promotion_action'
left outer join activators a
on pa.activator_id = a.id
left outer join adjustments adj
on pa.id = adj.originator_id
and pa.originator_type = 'promotion_action'
) subDetail
) subAggregate