使用PHP将传入的数字添加到MySQL单元格

Question

I am trying to add a number to a number already in a MySQL table. I am using POST to pass in the number.

    <?php
    require "connection.php";

    $id = $_POST["id"];
    $number = $_POST["number"];

Do I have to make 2 separate queries, one to retrieve the current value and set is as a variable and one to insert the new value by adding the number to the variable or can I accomplish this with one query with something like this:

    $update_query = "update Table set value = (value + $number) where id like '$id';" 

Answer 1

update field to add value to existing value:

UPDATE table SET value = value + $number WHERE id = $id;

update field to contact value to existing value:

use the CONCAT function :

UPDATE table SET value= CONCAT('$number',value) WHERE id=$id;