Get selected value from drop down which is populated from a database

Question

I want to get the selected SystemID from my drop down menu which is populated by a database. I have named the drop down"data3"

Drop down from database is all working, it is displaying all the SystemIDs from my table.

Code below:

<select id ="data3" style="position:relative; top:-70px; left: 3.6%;" 
name="data3" class="btn btn-light btn-sm dropdown-toggle">
    <option value="SystemID">SystemID</option>
    <?php
        $sql = "SELECT DISTINCT SystemID FROM MyTable ORDER BY 
        SystemID";
    $result = sqlsrv_query($conn, $sql);
    while ($row = sqlsrv_fetch_array($result, SQLSRV_FETCH_ASSOC)) {
        echo "<option value=\"\">" . $row['SystemID'] . "</option>";
        }
    ?>
  </select>

How do I get the selected value from that drop down? I have tried doing

var data3=$("#data3").val();

But this returns nothing

for value use this https://stackoverflow.com/questions/1643227/get-selected-text-from-a-drop-down-list-select-box-using-jquery..This question is duplicated — Imran Ahmad Shahid, Mar 04 '19 at 12:21
@ImranAhmadShahid So `var data3=#("#data3 option:selected").val();` or `var data3=$("#data3 option:selected").val();` — Danny, Mar 04 '19 at 12:22
Your answer does not work @ImranAhmadShahid It returns nothing — Danny, Mar 04 '19 at 12:23
use jquery selector $, by mistake # was inserted, I have edited — Imran Ahmad Shahid, Mar 04 '19 at 12:24
[Here's a MDN link](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/option) about the HTML-tags ` — M. Eriksson, Mar 04 '19 at 12:26
@MagnusEriksson but in my case, i'm getting my drop down populated from a database.. ? — Danny, Mar 04 '19 at 12:27
Just echo the value you want in the correct place. You already have code to echo the values from the database (the text for each option). Something like: `value=\"" . $row['TheDbColumnToUseAsValue'] . "\"` — M. Eriksson, Mar 04 '19 at 12:29
@ImranAhmadShahid - In PHP, you concatenate strings using `.`, not `+`. — M. Eriksson, Mar 04 '19 at 12:31
@MagnusEriksson thanks for refresh. I haven't work in php since 4 years :P — Imran Ahmad Shahid, Mar 04 '19 at 12:33
Your PHP-code generates HTML code. You're looping through a result set from a database query and are creating new ` — M. Eriksson, Mar 04 '19 at 12:34
That's not what I told you to do. Do either `""` or `""` (which works if the value and the text are the same). — M. Eriksson, Mar 04 '19 at 12:42

Vidal · Answer 1 · 2019-03-04T12:41:28.680

0

Use the ternary operator to check if the value coming from the database match the one from the select and mark it as selected. Please note that you must have a list of all the values of the select/option statement to be able to compare.

$row['SystemID'] == $value?'selected':''

echo "<option value='".$row['SystemID'] ."' ". ($row['SystemID'] == $value?'selected':'') ."  >" . 
        $row['SystemID'] . 
     "</option>";

edited Mar 04 '19 at 12:41

answered Mar 04 '19 at 12:27

Vidal

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Also, when using a ternary operator when you concatenate strings, you usually need to group it with parentheses. `string ' . ($condition ? 'on true' : 'on false') . ' string`. Otherwise, PHP won't know when the `on false` results ends and the rest begins. – M. Eriksson Mar 04 '19 at 12:39
is not fully necessary but added the change for easy reading and identifying the ternary operator. thanks – Vidal Mar 04 '19 at 12:43
_"is not fully necessary"_ - As mentioned in my previous comment, in this context those parentheses are _very_ necessary, or the output will simply be wrong. [Here's a demo](https://3v4l.org/cKYb4) – M. Eriksson Mar 04 '19 at 12:48
you are correct, I use them in Laravel a lot inside {{}} and they are change to – Vidal Mar 04 '19 at 12:50

Get selected value from drop down which is populated from a database

1 Answers1