javascript - 保存新的 div 顺序避免重复 sql 查询

Question

<div class="artitle" data-id=1>lorem</div>
<div class="artitle" data-id=2>ipsum</div>
//and so on - about 500 divs

我使用 javascript 对 div 上下重新排序，需要将这个新顺序保存在数据库中(ind 列)。

let ids = $.map($('.artitle'), (e) => $(e).data('id')).join(',');
let inds = $.map($('.artitle'), (e) => $(e).index()).join(',');
//$.post... - send the variables on remote server

php

$aids = explode(',', $ids);
$ainds = explode(',', $inds);
foreach($aids as $key=>$val){
    $sql = "update arts set ind = :aind where id = :aid";
    $st = $db->prepare($sql);
    $st->execute([
        ":aind" => $ainds[$key],
        ":aid" => $val
    ]);
}

它有效，但是否有更好的方法 - 避免重复 sql 查询 500 次？

Answer 1

您需要使用 PHP 构建单个 mysql 查询并使用 INSERT INTO mysql 功能(multiple updates in one query 更新多行，下面是您应该如何做(我还没有使用准备好的声明，这是为了让你弄清楚，因为现在你已经知道如何以编程方式构建查询):

PHP

$aids = explode(',', $ids);
$ainds = explode(',', $inds);

$timeStart = microtime(true);

$sqlQuery = 'INSERT INTO arts (id,ind) ';

foreach($aids as $key=>$val){

    $sqlQuery .= "VALUES ($val,$ainds[$key]),";

}

#REMOVE THE LAST COMA(,)
$sqlQuery = substr($sqlQuery, 0, -1);

$sqlQuery .= 'ON DUPLICATE KEY UPDATE id=VALUES(id),ind=VALUES(ind);';

#RUN THIS AS REQUIRED, YOU GOT YOUR DYNAMICALLY GENERATED MYSQL MULTIPLE UPDATE STATEMENT#
#$sqlQuery;

$timeEnd = microtime(true);
$time = $timeEnd - $timeStart;

echo "Took $time seconds\n";