SQL 查询组按邮政编码多个总和

Question

I have following data:

ID	Weight	Postcode	Year
1	23	56222	2022
2	24	56332	2022
3	50	56442	2022
4	22	62331	2022
5	80	72130	2022

and i want to query it that i get the data like this: Grouped by Postcode and splitted in different weight ranges. and then just Count of the amount of entrys.

Postcode/Weight	0-20	21-40	41-60	61-80	81-100
56	0	2	1	0	0
62	0	1	0	0	0
72	0	0	0	1	0

Is there any way to query this in SQL?

Answer 1

Try this one.

Query:

SELECT 
    p.postcode, 
    COUNT(p20.id) as "0-20",
    COUNT(p40.id) as "21-40",
    COUNT(p60.id) as "41-60",
    COUNT(p80.id) as "61-80",
    COUNT(p100.id) as "81-100"
FROM packs p 
    LEFT JOIN packs p20 ON p20.postcode=p.postcode AND p20.weight < 20  
    LEFT JOIN packs p40 ON p40.postcode=p.postcode AND p40.weight >= 21 AND p40.weight <= 40 
    LEFT JOIN packs p60 ON p60.postcode=p.postcode AND p60.weight >= 41 AND p60.weight <= 60
    LEFT JOIN packs p80 ON p80.postcode=p.postcode AND p80.weight >= 61 AND p80.weight <= 80
    LEFT JOIN packs p100 ON p100.postcode=p.postcode AND p100.weight >= 81 AND p100.weight <= 100 
GROUP by postcode;

Result: Table