If command breaking my PHP script

Question

I don't really know what's going on here.

If I have this as my code:

if($_POST['expOncology'] !="") {
    $varOnc = $_POST['expOncology'];

    if ($varOnc="min") {
        $sql_extra[] = "(exp_onc='minimal expertise' OR exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc="some") {
        $sql_extra[] = "(exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc="high") {
        $sql_extra[] = "(exp_onc='high level of expertise' OR exp_onc='expert')";
    }
}

It works fine and the proper results are shown.

However, if I add one more if block, to make it this:

if($_POST['expOncology'] !="") {
    $varOnc = $_POST['expOncology'];

    if ($varOnc="min") {
        $sql_extra[] = "(exp_onc='minimal expertise' OR exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc="some") {
        $sql_extra[] = "(exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc="high") {
        $sql_extra[] = "(exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc="expert") {
        $sql_extra[] = "(exp_onc='expert')";
    }
}

It does not work as intended at all, even if I'm not even selecting "expert" from the drop down list. Shouldn't that code not even run if expOncology isn't set to expert? Why is even affecting the code if I'm not satisfying its conditions to run?

I don't know, from when single `=` is used for comparison?!?!?! — Morteza Tourani, Jul 25 '16 at 20:57
See [Comparison Operators](http://php.net/manual/en/language.operators.comparison.php) — showdev, Jul 25 '16 at 20:57
All conditionals are currently met. Do you maybe mean the SQL later fails? — chris85, Jul 25 '16 at 20:58
that's weird, I was accidentally using single = for every other comparison before this and it was working fine... — Luke, Jul 25 '16 at 20:59
Also if comparing the same variable multiple times consider using `switch`. http://php.net/manual/en/control-structures.switch.php — chris85, Jul 25 '16 at 21:02

score 0 · Answer 1 · answered Jul 25 '16 at 21:00

Condition like $varOnc="something" will always return true.

You should use a == or === (if you want check the data types). Your code should look like this

if($_POST['expOncology'] != "") {
    $varOnc = $_POST['expOncology'];

    if ($varOnc == "min") {
        $sql_extra[] = "(exp_onc='minimal expertise' OR exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc == "some") {
        $sql_extra[] = "(exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc == "high") {
        $sql_extra[] = "(exp_onc='high level of expertise' OR exp_onc='expert')";
    }

    if ($varOnc == "expert") {
        $sql_extra[] = "(exp_onc='expert')";
    }
}

score 0 · Accepted Answer · answered Jul 25 '16 at 21:01

Try

if($_POST['expOncology'] !="") {
  $varOnc = $_POST['expOncology'];
  if ($varOnc=="min"){
    $sql_extra[] = "(exp_onc='minimal expertise' OR exp_onc='some     expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
   }
  if ($varOnc=="some"){
    $sql_extra[] = "(exp_onc='some expertise' OR exp_onc='high level of expertise' OR exp_onc='expert')";
  }
 if ($varOnc=="high"){
    $sql_extra[] = "(exp_onc='high level of expertise' OR exp_onc='expert')";
 }
}

with == it's better to compare ;)

If command breaking my PHP script

2 Answers2