query dropdown menu value

[meow]

Hi..

I have a dropdown menu thats pull value from MySQL.
Now i want to query the selected value from dd menu so then it will display a list that match with it in database without submit the page.
Do i have to use onChange function and how?
Sorry i'm new to javascript.

Thanks in advance.

[beetle]

Not sure I get what you are asking. Can you be more specific, maybe a code snippet to help us understand?

[meow]

Ok My problem is something like this.

This is my dd menu. (Actually its pullout data from MySQL)

<select name="semester" size="1">
  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
  <option value="4">4</option>
</select> 

1. Let say user select 1.
2. Query the database based on selected value.
$query = "SELECT * FROM semester WHERE sem = '1'"
3. Then it will display a result that match with the query without submit the page.

Any ideas?
Please help.

[beetle]

Well, you couldn't acutally do this w/o submitting the page. However, if you devised an algorithm to stuff all the results from SELECT * FROM semester into a javascript array, then you can use the onChange() event attached to the SELECT to display what you need. Something like this perhaps

$result = mysql_query("SELECT * FROM semester");
$fetch = mysql_fetch_array($result);
echo("<script>\n var arr = new Array();\n");
$count = 0;
foreach($fetch as $val) {
    echo("arr[".$count."] = '".$val."\n");
    count++;
    }
echo("</script>\n"); 

[meow]

Hi.
I've tried that one but it doesnt work.
I'm more into php rather than javascript.

Is there any other way?

[beetle]

hmmm, maybe a bit more like this...

$result = mysql_query("SELECT * FROM semester");
echo("<script>\n var arr = new Array();\n");
$countOuter = 0;
$countInner = 0;
foreach (mysql_fetch_array($result) as $tempArr)
    {
    echo("arr[".$countOuter."] = new Array()\n");
    $countInner = 0;
    foreach($tempArr as $val) 
        {
        echo("arr[".$countOuter."][".$countInner."] = '".$val."\n");
        $countInner++;
        }
    $countOuter++;    
    }

echo("</script>\n"); 

This may need a little debugging, but that *SHOULD* populate your array properly. If it does, let me know, and we can move on the using the SELECT to switch it all

[meow]

Ok. with changes at
foreach($tempArr as $val) to
foreach(mysql_fetch_array($result) as $val) it will give me array like this
arr[0] = new Array()
arr[0][0] = '2
arr[0][1] = '2
arr[0][2] = '2

This array give redundant data. One silly question from me is how the array will looklike?

Thanks.

[beetle]

This worked for me

http://www.lanwizards.com/test.php

In put the PHP source on the page in HTML. You can View>>Source to see the javascript array.

My test semesters table looks like this

+----+--------+----------+
| id |  name  |  length  |
+----+--------+----------+
| 1  | Fall   | 3 months |
| 2  | Winter | 3 months |
| 3  | Spring | 3 months |
| 4  | Summer | 1 month  |
+----+--------+----------+

[meow]

Okies
Thanks I got it.
Whats next?

[Andrew-J2000]

"Well, you couldn't acutally do this w/o submitting the page", this is possible with remote scripting or using the xml dom.

heres an example of this

http://www.ashleyit.com/rs/jsrs/select/php/select.php

also
http://www.w3schools.com/xml/xml_http.asp

any way try that