Problems when showing my subcategory

I made the changes you told me I tried too, the same way I get the error that I'm wrongly implementing the implode or in the array or string.

The query on line 25 fails because the '...IN ('".$base."')...' must contain a series of values separated by commas inside the parentheses, type (1,2,3,4) , and you are including a string that comes from doing a implode separated by " " instead of "," .

$base is a string since you fill it with a string when doing implode , not an array, do not put $base[] .

Try these changes.

Added to the answer: what was left to correct is that the implode must be done after the foreach, when the data array is already there, not while the elements are added.

$data = array ();
foreach ($resultado as $elemento) {
  $data[] = $elemento["id"];
}
$string = implode (",",$data);