前言
节前公司业务方需要做一個統計報表,这个报表用于统计当月估计几个明星品的销售情况,而我们的数据是按行存储的就是日期|产品|渠道|销售额
这样,说是也奇了怪了,我们买的报(guan)表(yuan)系(la)统(ji) 竟然不能容易地实现。。。,于是我看了看,然后想了想,发现是可以通过sql算出这样一个报表(多亏了postgresql的高阶函数),然后直接将数据输出到报表系统 完事兒~ ,以下 我將sql關鍵部分描述下,至於對前端展示有興趣的同學可留言,可考慮作一節講講哈~
报表
首先,業務需要的報表長這樣子的,看起來似乎還OK哈~
接下來我先給出我的測試脚本(均測試&無bug)~
表结构
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drop table if EXISTS report1 ;
CREATE TABLE "report1" (
"id" numeric (22) NOT NULL ,
"date" date NOT NULL ,
"product" varchar (100),
"channel" varchar (100),
"amount" numeric (20,4)
);
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表注释
字段 | 描述 |
---|---|
id | 主键 |
date | 日期 |
product | 产品 |
channel | 渠道 |
amount | 销售额 |
表数据
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INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051726328010100000' , '2021-05-04' , '产品1' , '京东' , '8899.0000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051726328010100001' , '2021-05-04' , '产品2' , '京东' , '99.0000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100010' , '2021-05-04' , '产品1' , '天猫' , '230.0000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100011' , '2021-05-04' , '产品2' , '天猫' , '9.9000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100011' , '2021-05-04' , '产品3' , '线下门店' , '10.1000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100000' , '2021-05-04' , '产品1' , '其它' , '10' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100099' , '2021-05-04' , '产品2' , '其它' , '20000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100033' , '2021-05-01' , '产品1' , '其它' , '20000' );
INSERT INTO "report1" ( "id" , "date" , "product" , "channel" , "amount" ) VALUES ( '2105051727068010100044' , '2021-05-01' , '产品3' , '线下门店' , '12345' );
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思考
如果你看到這裏請稍稍思考下,一開篇我説過我們的數據是按 日期|产品|渠道|销售额
這樣按行存儲的,以上截圖大家一看就懂,然後再看看開篇的報表截圖,我想大家可以同我一樣可以分析出以下幾點:
- 報表縱向看大致分三部分
一部分是前一日產品銷售明細
然後一部分是前一日產品渠道產品合計
最後一部分是按渠道做的月統計
- 報表橫向看大致分兩部分
一部分是前一日的數據
另一部分則是月份匯總數據
最後一部分則是所有渠道的產品合計、日合計、月合計
好了,問題來了,如何做呢,我是這麽想的:首先要很清楚的是你的sql大致分兩大部分(兩個子查詢)
一部分是前一日的數據另一部分則是月份匯總數據
最後需要將兩部分數據做聯表查詢,這樣太贊了,似乎完成了報表的80%,至於最後一行的求總,這裏先賣個關子哈~
第一部分數據(前一日的數據)
我想我們立馬能做的第一部分sql恐怕就是行專列吧(似乎這是最容易實現的)
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select
channel,
sum ( case product when '产品1' then amount end ) as c1,
sum ( case product when '产品2' then amount end ) as c2,
sum ( case product when '产品3' then amount end ) as c3
from report1
group by channel ;
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sql似乎沒什麽問題,但是我們少了一列,對那就是按渠道日合計
,當然如果您對postgresql窗口函數熟悉的話,這裏實現的方式估計你已經猜到了(窗口over
函數),上sql...
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select
channel,
day_sum,
sum ( case product when '产品1' then amount end ) as c1,
sum ( case product when '产品2' then amount end ) as c2,
sum ( case product when '产品3' then amount end ) as c3
from
( select *, sum (amount) over (partition by channel) as day_sum from report1 where date =to_date( '2021-05-04' , 'yyyy-MM-dd' ) ) as t1
group by t1.channel ,t1.day_sum;
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哈哈,上圖的day_sum
估計大家很熟悉了吧,哈哈哈~
看來已經成功地完成了日數據
部分,這裏可能的難點可能就兩點
-
一是使用聚合函數(
sum
)+分組(group by
)做行專列(當然postgresql
也有其他很好用的行專列擴展,這裏就不介紹啦~)另一個是使用窗口函數(over
)對明細提前做按渠道的窗口匯總
,這樣渠道日合計(行)的數據就有啦~
想想是不是很容易,接下來我們看看第二部分數據怎麽獲取~
第二部分數據(月份匯總數據)
月份匯總的數據看似簡單的可怕,如果您熟練掌握postgresql中的日期處理的話估計分分鐘就能搞定,這裏就不耍大刀了,直接放出sql,哈哈哈
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select
channel, sum (amount) as month_sum from report1
where
date >= date (date_trunc( 'month' ,to_date( '2021-05-04' , 'yyyy-MM-dd' ))) and date < date (date_trunc( 'month' ,to_date( '2021-05-04' , 'yyyy-MM-dd' )) + '1 month' )
group by
channel
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報表數據最終求解
現在,我們將求解的兩部分數據按渠道channel
字段做inner join
合并以上兩部分數據,合并后的數據大致是這樣子的
這個是sql
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select
ttt.channel,
sum (ttt.day_sum) as day_sum,
sum (ttt.month_sum) as month_sum,
sum (ttt.c1) as c1,
sum (ttt.c2) as c2,
sum (ttt.c3) as c3
from (
select tt1.*,tt2.month_sum from
(
select
channel,
day_sum,
sum ( case product when '产品1' then amount end ) as c1,
sum ( case product when '产品2' then amount end ) as c2,
sum ( case product when '产品3' then amount end ) as c3
from
( select *, sum (amount) over (partition by channel) as day_sum from report1 where date =to_date( '2021-05-04' , 'yyyy-MM-dd' ) ) as t1
group by t1.channel ,t1.day_sum
) as tt1 left join
(
select channel, sum (amount) as month_sum from report1 where date >= date (date_trunc( 'month' ,to_date( '2021-05-04' , 'yyyy-MM-dd' ))) and date < date (date_trunc( 'month' ,to_date( '2021-05-04' , 'yyyy-MM-dd' )) + '1 month' ) group by channel
) as tt2 on tt1.channel = tt2.channel
) ttt
GROUP BY ttt.channel
order by channel asc
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看,匯總的數據已經有了,已經可以算作是最終結果了(如果你需要報表系統來計算匯總行數據的話),當然 ,我們的報表系統過於繁瑣(不是不能做,而是太麻煩),需要你將做好的菜喂給它吃,這時,該怎麽辦呢。。。,哈哈哈 我們似乎忘記了很久不用的rollup
函數(一開始我也沒發現有這麽個函數哈哈),試試看吧
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select
ttt.channel,
sum (ttt.day_sum) as day_sum,
sum (ttt.month_sum) as month_sum,
sum (ttt.c1) as c1,
sum (ttt.c2) as c2,
sum (ttt.c3) as c3
from (
select tt1.*,tt2.month_sum from
(
select
channel,
day_sum,
sum ( case product when '产品1' then amount end ) as c1,
sum ( case product when '产品2' then amount end ) as c2,
sum ( case product when '产品3' then amount end ) as c3
from
( select *, sum (amount) over (partition by channel) as day_sum from report1 where date =to_date( '2021-05-04' , 'yyyy-MM-dd' ) ) as t1
group by t1.channel ,t1.day_sum
) as tt1 left join
(
select channel, sum (amount) as month_sum from report1 where date >= date (date_trunc( 'month' ,to_date( '2021-05-04' , 'yyyy-MM-dd' ))) and date < date (date_trunc( 'month' ,to_date( '2021-05-04' , 'yyyy-MM-dd' )) + '1 month' ) group by channel
) as tt2 on tt1.channel = tt2.channel
) ttt
group by rollup (ttt.channel)
order by channel asc
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數是對的,意味著我們成功了~
總結
如果您肯下功夫學,postgresql
世界有很多精彩的東西,當然也有一些東西對比mysql顯得繁瑣些,不過本著學習的心態,我們縂能剋服這些,同時我們還是能做出超出我們自身能力範疇
的東西的,哈哈,各位加油哦~
下章,我將講一講如何實現通過sql實現前端合并單元格的效果,是不是很神奇(我保證你全網搜不到), 希望不翻車,哈哈哈~
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原文链接:https://www.cnblogs.com/funnyzpc/p/14732165.html