如何从sqlite数据库中的每个user_id中选择最后5个结果? [英] How to select last 5 results from each user_id in an sqlite database?

问题描述

我有一个像这样的num"表的数据库

I have a database with "num" table like this

user_id  |  number   |  unix_time
-----------------------------
123         2           xxxxxxxx
123         40          xxxxxxxx
123         24          xxxxxxxx
333         23          xxxxxxxx
333         67          xxxxxxxx
854         90          xxxxxxxx

我想选择每个 user_id 插入的最后 5 个数字，但我不知道该怎么做.

I'd like to select the last 5 numbers inserted by each user_id, but I can't figure out how to do it.

我试过了:

SELECT b.n, a.user_id
FROM num a
JOIN num b on a.user_id = b.user_id
WHERE (
    SELECT COUNT(*)
    FROM num b2
    WHERE b2.n <= b.n
        AND b2.user_id = b.user_id
) <= 5

推荐答案

如果要从 SQlite 数据库中选择最后 5 条记录，请使用查询SELECT * FROM table_name ORDER BY user_id DESC LIMIT 5;使用此查询，您可以选择最后 n 笔交易...希望对您有所帮助

If you want to select last 5 records from the SQlite database then use query SELECT * FROM table_name ORDER BY user_id DESC LIMIT 5; Using this query you can select last n transactions...Hope I helped you

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