pgsql - 显示前 10 名产品的销售额和其他产品 'others' 及其总销售额

Question

我有一个名为 "products" 的 table，它有 100 条销售明细记录。我的要求太简单了，我做不到。

我需要显示销售额排名前 10 位的产品名称，其他产品名称为 "others" 及其销售额。所以我的 o/p 总共是 11 行。第 11 行应该是其他和所有剩余产品的销售额总和。谁能给我逻辑？

O/p应该是这样的,

      Name          sales
     ------         ----- 
1    colgate        9000
2    pepsodent      8000
3    closeup        7000
4    brittal        6000
5    ariies         5000
6    babool         4000
7    imami          3000
8    nepolop        2500
9    lactoteeth     2000
10   menwhite       1500
11   Others         6000 (sum of sales of remaining 90 products)

这是我的 sql 查询，

select case when rank<11 then prod_cat else 'Others' END as prod_cat,
total_sales,ID,rank from (select ROW_NUMBER() over (order by (sum(i.grandtotal)) desc) as rank,pc.name as prod_cat,sum(i.grandtotal) as total_sales, pc.m_product_category_id as ID`enter code here`
from adempiere.c_invoice i join adempiere.c_invoiceline il on il.c_invoice_id=i.c_invoice_id join adempiere.m_product p on p.m_product_id=il.m_product_id join adempiere.m_product_category pc on pc.m_product_category_id=p.m_product_category_id
where extract(year from i.dateacct)=extract(year from now())
group by  pc.m_product_category_id) innersql
order by  total_sales desc

o/p我得到的是，

prod_cat   total_sales     id           rank
--------   -----------     ---          ----
BSHIRT     4511697.63      460000015     1
BT-SHIRT   2725167.03      460000016     2
SHIRT      2630471.56      1000003       3
BJEAN      1793514.07      460000005     4
JEAN       1115402.90      1000004       5
GT-SHIRT   1079596.33      460000062     6
T SHIRT     446238.60      1000006       7
PANT        405189.00      1000005       8
GDRESS      396789.02      460000059     9
BTROUSER    393739.48      460000017    10
Others      164849.41      1000009      11
Others      156677.00      1000008      12
Others      146678.00      1000007      13

Answer 1

正如@e4c5 所建议的那样，使用 UNION:

select id, prod_cat, sum(total_sales) as total_sales
with
  totals as (
    select --pc.m_product_category_id as id,
           pc.name as prod_cat,
           sum(i.grandtotal) as total_sales,
           ROW_NUMBER() over (order by sum(i.grandtotal) desc) as rank
    from adempiere.c_invoice i
    join adempiere.c_invoiceline il on (il.c_invoice_id=i.c_invoice_id)
    join adempiere.m_product p on (p.m_product_id=il.m_product_id)
    join adempiere.m_product_category pc on (pc.m_product_category_id=p.m_product_category_id)
    where i.dateacct >= date_trunc('year', now()) and i.dateacct < date_trunc('year', now()) + interval '1' year
    group by pc.m_product_category_id, pc.name
    ),
  rankedothers as (
    select prod_cat, total_sales, rank
    from totals where rank <= 10
    union
    select 'Others', sum(total_sales), 11
    from totals where rank > 10
    )
select prod_cat, total_sales
from ranked_others
order by rank

此外，我建议使用 sargable 条件，如上面的条件，它比您实现的条件稍微复杂一些，但通常值得付出额外的努力。