why when I post a form element I get undefined index error?

Question

I am retrieving some data from the database and insert them in to the table using the following code . I am trying to make each row one form and once the user click the button I want to send the information to sub.php to store it in DB.Currently the problem is when I post the info i get undefined value . Here is my code :

   while($row = $result->fetch_assoc()) {
                                echo '<form  method="Post" action="sub.php" ><tr>
                                            <td class="text-center" style="border-color:yellow;color:white;">'
                                                .$row["name"] .
                                            '</td>
                                            <td class="text-center" style="border-color:yellow;color:white;">'
                                                .$row["course_name"] .
                                            '</td>
                                            <td class="text-center" style="border-color:yellow;color:white;">'
                                                .$row["course_lec"] .
                                            '</td>
                                            <td class="text-center"  style="border-color:yellow;color:white;">'
                                                .$row["course_sem"] .
                                            '</td>
                                            <td class="text-center" style="border-color:yellow;color:white;" >
                                                <select  style="background-color: #222222; border: none; name="q1">
                                                 <option value="0">0</option> 
                                                  <option value="1">1</option>
                                                  <option value="2">2</option>
                                                  <option value="3">3</option>
                                                  <option value="4">4</option>
                                                  <option value="5">5</option>
                                                  <option value="6">6</option>
                                                  <option value="7">7</option>
                                                  <option value="8">8</option>
                                                  <option value="9">9</option>
                                                  <option value="10">10</option>

                                            </select>   

                                            </td>
                                            <td class="text-center" style="border-color:yellow;color:white;">
                                            <select  style="background-color: #222222; border: none; name="q2">
                                                 <option value="0">0</option> 
                                                  <option value="1">1</option>
                                                  <option value="2">2</option>
                                                  <option value="3">3</option>
                                                  <option value="4">4</option>
                                                  <option value="5">5</option>
                                                  <option value="6">6</option>
                                                  <option value="7">7</option>
                                                  <option value="8">8</option>
                                                  <option value="9">9</option>
                                                  <option value="10">10</option>

                                            </select>    
                                            </td>
                                            <td class="text-center"  style="border-color:yellow;color:white;">
                                                   <select  style="background-color: #222222; border: none; name="q3">
                                                 <option value="0">0</option> 
                                                  <option value="1">1</option>
                                                  <option value="2">2</option>
                                                  <option value="3">3</option>
                                                  <option value="4">4</option>
                                                  <option value="5">5</option>
                                                  <option value="6">6</option>
                                                  <option value="7">7</option>
                                                  <option value="8">8</option>
                                                  <option value="9">9</option>
                                                  <option value="10">10</option>

                                            </select>   
                                            </td>
                                            <td class="text-center" style="border-color:yellow;color:white;">
                                                   <select  style="background-color: #222222; border: none; name="q4">
                                                 <option value="0">0</option> 
                                                  <option value="1">1</option>
                                                  <option value="2">2</option>
                                                  <option value="3">3</option>
                                                  <option value="4">4</option>
                                                  <option value="5">5</option>
                                                  <option value="6">6</option>
                                                  <option value="7">7</option>
                                                  <option value="8">8</option>
                                                  <option value="9">9</option>
                                                  <option value="10">10</option>

                                            </select>   
                                            </td>
                                            <td class="text-center" class="text-center" style="border-color:yellow;color:white;">
                                                   <select  style="background-color: #222222; border: none; name="q5" >
                                                 <option value="0">0</option> 
                                                  <option value="1">1</option>
                                                  <option value="2">2</option>
                                                  <option value="3">3</option>
                                                  <option value="4">4</option>
                                                  <option value="5">5</option>
                                                  <option value="6">6</option>
                                                  <option value="7">7</option>
                                                  <option value="8">8</option>
                                                  <option value="9">9</option>
                                                  <option value="10">10</option>

                                            </select>   
                                            </td>
                                            <td class="text-center" class="text-center" style="border-color:yellow;">
                                                <button type="submit"  class="btn btn-primary btn-xs" >submit</button>
                                            </td>

                                           </form> ' 

                                            ;
                             }

                    }

and in sub.php I have :

<?php


include ("conn.php") ; 
session_start();


$selectOption = $_POST["q1"];




?>

and for better understanding I've put the image there too

Possible duplicate of [Reference - What does this error mean in PHP?](https://stackoverflow.com/questions/12769982/reference-what-does-this-error-mean-in-php) — Jelmergu, May 31 '17 at 11:10
Most probably the select box with the name q1 haven't selected before submitting. — Reiah Paul Sam, May 31 '17 at 11:13

score 1 · Accepted Answer · answered May 31 '17 at 11:21

You don't have a closing quote on your style="" attribute in your select tag:

<select  style="background-color: #222222; border: none; name="q1">

Hence the field isn't getting named q1, fix it like this:

<select  style="background-color: #222222; border: none;" name="q1">

Same goes for your other questions.

score -1 · Answer 2 · answered May 31 '17 at 11:15

-1

you may have to try :

if(!empty $_POST["q1"])
{
    $selectOption = $_POST["q1"];
}

Test existing variables to be sure you won't get an index error. Hope it was helping!

answered May 31 '17 at 11:15

Younes Diouri

61
1
7

This is invalid syntax. – Enstage May 31 '17 at 11:19

why when I post a form element I get undefined index error?

2 Answers2