php - 如何在php中生成下一个序列号并比较第一个序列号？

Question

代码：

if(isset($_POST['submit']))
{
    $number = 1000;
    $number++;
    $unique = strval($number);
    $product_id = "LTC_".$unique;
    $query = "insert into stock(`product_id`)values('".$product_id."')";
    //echo $query;

    $result = mysqli_query($con,$query);
    if($result==true)
    {
        $msg = "<div class='alert alert-success'>Record Save Successfully</div>";
    }
    else
    {
        $msg = "<div class='alert alert-danger'>Unable to Save Please Try Again !!!</div>";
    }
}

在这段代码中，我有一个变量，即$product_id. 现在我在这里做什么我product_id在表中插入值假设下一个值将product_id是。现在我想以一系列方式生成一个新号码，如果我删除任何号码，它将永远不会再重复。那么，我该怎么做呢？ 10011002product_id

标签： php

Answer 1

尝试这个

$sql = mysqli_query($con,"select max(product_id) as product_id from stock");
$fet = mysqli_fetch_assoc($sql);
$ides = $fet['product_id'];
$number = 1000;
$number++;
$unique = strval($number);
if($unique==$ides || $unique!=$ides)
{
    $new_id = ++$ides;
}
if(isset($_POST['submit']))
{
    $product_id = $new_id;
    //your custom code here
}