MySQL INNER JOIN 从第二个表中只选择一行

2023-06-25数据库问题
1

本文介绍了MySQL INNER JOIN 从第二个表中只选择一行的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着跟版网的小编来一起学习吧!

问题描述

我有一个 users 表和一个 payments 表,对于每个有付款的用户,在 payments表.我想选择所有有付款的用户,但只选择他们最近的付款.我正在尝试这个 SQL,但我以前从未尝试过嵌套 SQL 语句,所以我想知道我做错了什么.感谢帮助

I have a users table and a payments table, for each user, those of which have payments, may have multiple associated payments in the payments table. I would like to select all users who have payments, but only select their latest payment. I'm trying this SQL but i've never tried nested SQL statements before so I want to know what i'm doing wrong. Appreciate the help

SELECT u.* 
FROM users AS u
    INNER JOIN (
        SELECT p.*
        FROM payments AS p
        ORDER BY date DESC
        LIMIT 1
    )
    ON p.user_id = u.id
WHERE u.package = 1

推荐答案

您需要有一个子查询来获取每个用户 ID 的最新日期.

You need to have a subquery to get their latest date per user ID.

SELECT  a.*, c.*
FROM users a 
    INNER JOIN payments c
        ON a.id = c.user_ID
    INNER JOIN
    (
        SELECT user_ID, MAX(date) maxDate
        FROM payments
        GROUP BY user_ID
    ) b ON c.user_ID = b.user_ID AND
            c.date = b.maxDate
WHERE a.package = 1

这篇关于MySQL INNER JOIN 从第二个表中只选择一行的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!

The End

相关推荐

Mysql目录里的ibtmp1文件过大造成磁盘占满的解决办法
ibtmp1是非压缩的innodb临时表的独立表空间,通过innodb_temp_data_file_path参数指定文件的路径,文件名和大小,默认配置为ibtmp1:12M:autoextend,也就是说在文件系统磁盘足够的情况下,这个文件大小是可以无限增长的。 为了避免ibtmp1文件无止境的暴涨导致...
2025-01-02 数据库问题
151

按天分组的 SQL 查询
SQL query to group by day(按天分组的 SQL 查询)...
2024-04-16 数据库问题
77

SQL 子句“GROUP BY 1"是什么意思?意思是?
What does SQL clause quot;GROUP BY 1quot; mean?(SQL 子句“GROUP BY 1是什么意思?意思是?)...
2024-04-16 数据库问题
62

MySQL groupwise MAX() 返回意外结果
MySQL groupwise MAX() returns unexpected results(MySQL groupwise MAX() 返回意外结果)...
2024-04-16 数据库问题
13

MySQL SELECT 按组最频繁
MySQL SELECT most frequent by group(MySQL SELECT 按组最频繁)...
2024-04-16 数据库问题
16

在 Group By 查询中包含缺失的月份
Include missing months in Group By query(在 Group By 查询中包含缺失的月份)...
2024-04-16 数据库问题
12