第一種:正常操作
SELECT
SUM(ddd) AS count_days,
CASE
WHEN aa.days >= 1
AND aa.days < 3 THEN
‘1-3’
WHEN aa.days >= 3
AND aa.days < 5 THEN
‘5-3’
ELSE
‘5+’
END AS groupby_days
FROM
(
SELECT
SUM(1) AS ddd,
days
FROM
tour_group
GROUP BY
days
) AS aa
GROUP BY
groupby_days;
第二種：真香函數
SELECT
elt(
INTERVAL (days, 1, 3, 5, 7, 10),
“1-3”,
“3-5”,
“5-7”,
“7-10”,
“10+”
) AS region,
count(*)
FROM
tour_group
GROUP BY
region;
