Postgres 15

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CREATE TABLE tab(score INT);

INSERT INTO tab(score) VALUES (1),(2),(9), (10), (11),(22),(23),(41);

CREATE TABLE

INSERT 0 8

SELECT WIDTH_BUCKET(score, 0, 50, 5) AS bucket_num, COUNT(*)
FROM tab
GROUP BY WIDTH_BUCKET(score, 0, 50, 5)
ORDER BY bucket_num;

bucket_num
count

1
3

2
2

3
2

5
1

SELECT 4

SELECT 
   CONCAT((WIDTH_BUCKET(score, 0, 50, 5)-1)*10, '-', WIDTH_BUCKET(score, 0, 50, 5)*10-1) AS bucket_num,
     COUNT(*)
FROM tab
GROUP BY  CONCAT((WIDTH_BUCKET(score, 0, 50, 5)-1)*10, '-', WIDTH_BUCKET(score, 0, 50, 5)*10-1)
ORDER BY bucket_num;

bucket_num
count

0-9
3

10-19
2

20-29
2

40-49
1

SELECT 4