CREATE TABLE IF NOT EXISTS members(
group_id BIGINT,
amount INT,
updated_date timestamp)
CREATE TABLE IF NOT EXISTS supergroups_ref(
group_id BIGINT PRIMARY KEY,
title TEXT DEFAULT NULL,
message_date timestamp)
CREATE TABLE IF NOT EXISTS supergroups(
group_id BIGINT PRIMARY KEY,
lang TEXT DEFAULT NULL,
last_date timestamp DEFAULT NULL)
成员中的数据示例
(3, 90, date)
(1, 15, date)
(2, 200, date)
(1, 28, date)
(2, 300, date)
(1, 80, date)
supergroups_ref中的数据示例:
(1, 'title', date)
(2, 'title2', date)
(3, 'title3', date)
(1, 'en', date)
(2, 'it', date)
(3, 'it', date)
从表中,成员仅获取按“updated\u date”DESC排序的最新行,并在超群上左连接它们,以便超群中的每个group\u id都具有最新的成员数量。
SELECT sub.group_id, sub.amount, sub.title
FROM (
SELECT s.group_id, m.amount, s_ref.title
FROM supergroups AS s
LEFT OUTER JOIN members AS m
ON m.group_id = s.group_id
LEFT OUTER JOIN supergroups_ref AS s_ref
ON s_ref.group_id = s.group_id
ORDER BY m.updated_date DESC
) AS sub
GROUP BY sub.group_id, sub.amount, sub.title
ORDER BY sub.amount DESC
-
-
预期结果为:
[(2, 200, 'title2'), (3, 90, 'title3'), (1, 15, 'title1')]
每个元素的第二个元素是最近的成员数量,因为该数量与日期一起存储在成员表中。元组是这样排序的