Undefined index & Undefined variable

wendymelon

I'm having problem with this code.

include('connect2db.php');
     $query = "SELECT employee.Emp_ID FROM employee,supervisor WHERE employee.Supervisor_ID = supervisor.Supervisor_ID AND supervisor.Supervisor_ID = '".$_SESSION['EmpID']."' ORDER BY employee.Emp_ID;";
     $result = mysql_query($query);
     while($row = mysql_fetch_array($result,MYSQL_NUM)){
         echo '<option>'.$row[0].'</option>';

 }
 echo '</select>';
 echo $_POST['ID'];
 echo '<input type="text" style="width: 250px; name="EmpName" id="EmpName" value="'.$EmpName.'"></input>';
 if(!empty($_POST['EmpID'])){
     $query2 = "SELECT Emp_Name FROM employee WHERE Emp_ID = '".$_POST['ID']."';";
     $result2 = mysql_query($query2);
     while($row2 = mysql_fetch_array($result2,MYSQL_NUM)){
         $EmpName =  $row[0];

     }
 }

Undefined index ID and undefined variable EmpName...

Why is it so? I've started my form as POST method.

Weedpacket

It's telling you that it has no idea what $EmpName is supposed to be: you've never given it a value (you don't actually do so until later). Do you not mean $_POST['EmpName']?

Similarly, for $POST['ID'] - if the form never sends back a value for its ID field, $POST['ID'] won't exist, and PHP will again complain if you then try to use it.

So the rule is: make sure your variables actually exist before you try to use them. You can use [man]isset[/man] and [man]empty[/man] for this - presumably, if those variables don't exist, then someone didn't fill out the form properly, and you want to know about that to deal with it.

wendymelon

I've changed my codes to these:

include('connect2db.php');
     $query = "SELECT employee.Emp_ID FROM employee,supervisor WHERE employee.Supervisor_ID = supervisor.Supervisor_ID AND supervisor.Supervisor_ID = '".$_SESSION['EmpID']."' ORDER BY employee.Emp_ID;";
     $result = mysql_query($query);
     echo '<select name="emID" id="emID" style="width: 100px;">';
     while($row = mysql_fetch_array($result,MYSQL_NUM)){
         echo '<option value=$row[0]>'.$row[0].'</option>';

 }
 echo '</select>';

 if(isset($_POST['emID'])){
     $EID = $_POST['emID'];
     $query2 = "SELECT Emp_Name FROM employee WHERE Emp_ID = '$EID';";
     $result2 = mysql_query($query2);
     while($row2 = mysql_fetch_array($result2,MYSQL_NUM)){
         $EmpName =  $row2[0];

     }
     echo '<input type="text" style="width: 250px; name="EmpName" id="EmpName" value="'.$EmpName.'"></input>';
 }

However, the textbox doesn't show the intended Emp_Name.....I doubt that there is an error in if(isset($_POST['emID']))

Does this IF means that if.....the option EmID is selected?

Weedpacket

Is the Emp_ID field used in the second query numeric? If it is, it doesn't need quotes.

And if you're only fetching one row there, you don't need the loop, either.