PHP MySQL查询其中x = $变量来自函数

Question

Why is this not working:

function listOrderComments ($factnr){
global $connection;

//$factnr = 123; //or $factnr = "123"; (Both work) 

$query = "SELECT * FROM orderstatus WHERE factuurnummer = '$factnr'"; 
$result = mysqli_query($connection, $query);

When I echo $factnr I get "123" back.

When I uncommented //$factnr = 123; my function is working.

Looked everywhere for a solution. check the type $factnr is (string).

Answer 1

You can go with:

$query = "SELECT * FROM orderstatus WHERE factuurnummer = ". $factnr;