我有很多针对存储在 MySQl 中的用户的推文。我正在尝试汇总每个用户(from_user)的所有推文文本(文本)并按月(created_at)对它们进行分组,如下所示:
from_user | month | fulltext
user1 | 1 | bla bla bla bla
user1 | 2 | bleh bleh bleh
user2 | 1 | bla bla bla bla
user2 | 2 | blub blub blub
我尝试编写如下 SQL 查询,但我无法弄清楚 MySQL 为何抱怨。我应该如何解决这个问题?
DROP TABLE IF EXISTS tempsumdate;
CREATE TABLE tempsumdate ENGINE=MyISAM CHARACTER SET utf8 COLLATE utf8_swedish_ci AS
SELECT tw.from_user, MONTH(tw.created_at) AS month, GROUP_CONCAT(tw.text) AS fulltext
FROM tweets AS tw
GROUP BY tw.from_user, month;