How to remove duplicate data from php database

How to remove duplicate data from PHP database: 1. Open the corresponding PHP file; 2. Connect to the database; 3. Use the native SQL statement "Db::execute('DELETE from data WHERE (phone) in.. ." Just remove duplicate data.

##The operating environment of this article: Windows 7 system, PHP version 7.1, DELL G3 computer

How to remove duplicate data from PHP database?

When developing projects, there is often duplicate data. How to remove duplicate data?

Today I will share with you a simple method,

Normally, whether it is developed using a framework or native PHP, there are few built-in deduplication methods. Basically, we need to embed the native SQL ourselves. The source code will be directly uploaded to you below

// 原生 sql 去重只留一条
$res = Db::execute(‘DELETE from data WHERE (phone) in
(SELECT phone from (SELECT phone FROM data GROUP BY phone HAVING COUNT(phone)>1) s1)
AND id NOT in (SELECT id from (SELECT id FROM data GROUP BY phone HAVING COUNT(phone)>1)
s2)
‘);
if($res){
$this->success (‘去重成功’, ‘index/maamiya’);
}else{
$this->error (‘已经没有重复的了’);
}

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