我想获得基于类型的4种类型的计数，因为我有4个单独的查询，但是我想只使用一个查询一次获得所有4个计数。
查询1:
SELECT count(*) as totalCount FROM orders INNER JOIN order_view ON orders.id= order_view.id
WHERE order_view.order_type = 'Type1'
查询2:
SELECT count(*) as totalCount FROM orders INNER JOIN order_view ON orders.id= order_view.id
WHERE order_view.order_type = 'Type2'
质疑三:
SELECT count(*) as totalCount FROM orders INNER JOIN order_view ON orders.id= order_view.id
WHERE order_view.order_type = 'Type3'
质疑四:
SELECT count(*) as totalCount FROM orders INNER JOIN order_view ON orders.id= order_view.id
WHERE order_view.order_type = 'Type4'
我正在通过Sequelize查找查询，似乎找不到任何文档。
使用条件聚合:
select
sum(ov.order_type = 'type1') as totalcount1,
sum(ov.order_type = 'type2') as totalcount2
sum(ov.order_type = 'type3') as totalcount3
sum(ov.order_type = 'type4') as totalcount4
from orders o
inner join order_view on o.id = ov.id
where ov.order_type in ('type1', 'type2', 'type3', 'type4')
不清楚为什么在查询中需要orders表。这可能只是做你想做的:
select
sum(ov.order_type = 'type1') as totalcount1,
sum(ov.order_type = 'type2') as totalcount2
sum(ov.order_type = 'type3') as totalcount3
sum(ov.order_type = 'type4') as totalcount4
from order_view
where ov.order_type in ('type1', 'type2', 'type3', 'type4')
