使用PHP在表单提交中将数据库表值增加一

Question

I am trying to increase the integer value of a database field value each time a form is submitted.

My table is simple. Only two relevant fields are Name and xp, and relevant values are Brian and 1.

I've gotten to the point I can call the PHP function on form submit, but I can't quite figure out how to declare the variable for the specific field I'm looking to increase ("1") or how to plug it into the UPDATE query.

If want to just update it with an arbitrary number, I know I can use...

if (isset($_POST['update'])){
$UpdateQuery = "UPDATE points SET xp=9 WHERE Name='Brian'";
mysql_query($UpdateQuery, $conn);

But how do I declare the existing ("1") from the database as a variable, and then plug it into the UPDATE query so that it's something like ....."UPDATE points SET xp=($result + 1) Where Name ='Brian'"; and where $result is the variable for the desired database value, in this case ("1").

Desired result is that the database value for xp where Name = Brian is now ("2").

I tried using the fetch/select functions to declare the database value as a variable but could not quite wrap my head around it. Guess I'm kind of new at this. Help would be really appreciated.

Answer 1

假设xp列xp为数字类型，则可以使用：

$UpdateQuery = "UPDATE points SET xp=xp + 1 WHERE Name='Brian'";