PHP &MySQL - 如何从两个表中删除用户记录 [英] PHP & MySQL - How to delete a users records from two tables

问题描述

您好，我是 PHP 的新手 &MySQL，我想知道如何使用 PHP & 从下面这两个表中删除所有 user_id 3 记录.MySQL?

Hello I'm new to PHP & MySQL and I was wondering how can I delete all of user_id 3 records from these two tables below using PHP & MySQL?

我的 MySQL 表

CREATE TABLE ls (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
skill VARCHAR(255) DEFAULT NULL,
experience VARCHAR(22) DEFAULT NULL,
self_grade VARCHAR(10) DEFAULT NULL,
date_created DATETIME NOT NULL,
date_updated DATETIME DEFAULT NULL,
PRIMARY KEY (id)
);


CREATE TABLE us (
id INT(13) UNSIGNED NOT NULL AUTO_INCREMENT,
skill_id INT(13) UNSIGNED NOT NULL,
user_id INT(13) UNSIGNED NOT NULL,
PRIMARY KEY (id)
);

us 表值

id  skill_id    user_id
9   7           3
10  8           3
11  9           3
12  10          3
13  17          6

ls 表值

id  skill   experience      self_grade  date_created            date_updated
7   html    5 years         A           2010-10-19 07:11:08     2010-10-19 07:12:06
8   jquery  10 years        B           2010-10-19 07:11:27     2010-10-19 07:12:06
9   css     1 year          NULL        2010-10-19 07:11:38     2010-10-19 07:12:06
10  php     2 years         C           2010-10-19 07:13:05     NULL
17  php     2 years         C           2010-10-19 07:19:05     NULL

推荐答案

您可以获取属于 user_id = 3 的所有行，然后使用生成的WHERE 子句.

You could fetch all rows belonging to user_id = 3 and then build a DELETE statement with a generated WHERE clause.

但是，我想知道您是否有不合适的表设计，因为您在用户和技能之间存在 m:n 关系，并且您想删除与 ID 为 3 的用户相关的所有技能.但这意味着用户和技能之间存在 1:m 关系(1 个用户拥有多项技能，而不是与他人共享技能).或者我做错了什么......?

But, however, I'm wondering if you have an inappropriate table design as you have a m:n relation between user and skill and you want to delete all skills the user with id 3 is related with. But this implicates a 1:m relation between user and skill (1 user has multiple skills, not sharing the skills with others). Or maybe I got something wrong...?

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