Help with passing drop down info

[sylunt1]

Greetings:

Iam having issues trying to figure out how to pass a selection from a drop down box to a different page to process it. I wish to have a submit button that takes the info selected and then finds an id number (which is listed in the city_id field). I can do this with a text box manual entry type form, but can't figure it out with the drop down.

Here's what we have so far:

$result = mysql_query ("SELECT bm_city.city_id, bm_city.city_name, bm_city.state_id, bm_state.state_name, bm_state.state_id
	FROM bm_city, bm_state 
	WHERE bm_city.state_id = bm_state.state_id
	ORDER BY bm_city.city_name") or die(mysql_error()); 

while($row = mysql_fetch_array($result))
{

$city_name = $row['city_name'];
$city_id = $row['city_id']; 
$state_name = $row['state_name'];
$state_id = $row['state_id'];

$optionList .= "<option value=". $city_id . $state_id . ">". $city_name . ", " . $state_name . "</option>";             

    }

// output 

echo "<select>";
echo $optionList;
echo "</select>";



?>

Thanks...

Chris

[easethan]

Looks lie you're missing a name for the drop-down box.

<?php

$result = mysql_query ("SELECT bm_city.city_id, bm_city.city_name, bm_city.state_id, bm_state.state_name, bm_state.state_id 
    FROM bm_city, bm_state 
    WHERE bm_city.state_id = bm_state.state_id 
    ORDER BY bm_city.city_name") or die(mysql_error());  

while($row = mysql_fetch_array($result)) 
{ 

$city_name = $row['city_name']; 
$city_id = $row['city_id'];  
$state_name = $row['state_name']; 
$state_id = $row['state_id']; 

$optionList .= "<option value=". $city_id . $state_id . ">". $city_name . ", " . $state_name . "</option>";              

    } 

// output 

echo "<select name=location>"; 
echo $optionList; 
echo "</select>"; 



?>

Then, on the processing page, you will call the $location variable, or $POST["location"] / $GET["location"] depending on the settings in php.ini and your form submit method(post / get).

[sylunt1]

OK I now have the button showing up.... but when it gets to the page it calls for it doesnt do anything....

Heres the processig page:

<?php  

$location = $_GET['location']; 

    	$result = mysql_query ("SELECT bm_city.city_id, bm_city.city_name, bm_city.state_id, bm_state.state_name, bm_state.state_id
FROM bm_city, bm_state 
	WHERE bm_city.city_name = '$city' and bm_state.state_id = bm_city.state_id") or die(mysql_error());  while($row = mysql_fetch_array($result))
	{

	$city_name = $row['city_name'];
	$city_id = $row['city_id'];		
	$state_name = $row['state_name'];

print $city_name . ', ' . $state_name . ' - ' . $city_id . '<br><br>';
}

?>  

Here is the dropdown page:

$result = mysql_query ("SELECT bm_city.city_id, bm_city.city_name, bm_city.state_id, bm_state.state_name, bm_state.state_id 
    FROM bm_city, bm_state 
    WHERE bm_city.state_id = bm_state.state_id 
    ORDER BY bm_city.city_name") or die(mysql_error());   

while($row = mysql_fetch_array($result))  
{  

$city_name = $row['city_name'];  
$city_id = $row['city_id'];   
$state_name = $row['state_name'];  
$state_id = $row['state_id'];  

$optionList .= "<option value=". $city_id . ">". $city_name . ", " . $state_name . "</option>";               

    }  

// output 

echo "<select name=location>";  

echo $optionList;  

echo "</select>";  


echo '<form method = "get"
      action = "cityid5.php">';

echo '<input type = "submit"></form>';      

[jabi]

In your select statement

WHERE bm_city.city_name = '$city' and bm_state.state_id = bm_city.state_id

you are calling for two variables, but have only passed one thru your form

option value=". $city_id . "

Suggestion:
"Glue" the variables together in your option value and then split them once it has been passed via the $_POST variables.

example:
option value = ".$city_id.",".$state_id.

When retrieved, you can use the explode() function to split it into the 2 separate variables for use in the select statement.

[sylunt1]

OK I now have the button showing up.... but when it gets to the page it calls for it doesnt do anything....

Heres the processig page:

<?php  

$location = $_GET['location']; 

    	$result = mysql_query ("SELECT bm_city.city_id, bm_city.city_name, bm_city.state_id, bm_state.state_name, bm_state.state_id
FROM bm_city, bm_state 
	WHERE bm_city.city_name = '$city' and bm_state.state_id = bm_city.state_id") or die(mysql_error());  while($row = mysql_fetch_array($result))
	{

	$city_name = $row['city_name'];
	$city_id = $row['city_id'];		
	$state_name = $row['state_name'];

print $city_name . ', ' . $state_name . ' - ' . $city_id . '<br><br>';
}

?>  

Here is the dropdown page:

$result = mysql_query ("SELECT bm_city.city_id, bm_city.city_name, bm_city.state_id, bm_state.state_name, bm_state.state_id 
    FROM bm_city, bm_state 
    WHERE bm_city.state_id = bm_state.state_id 
    ORDER BY bm_city.city_name") or die(mysql_error());   

while($row = mysql_fetch_array($result))  
{  

$city_name = $row['city_name'];  
$city_id = $row['city_id'];   
$state_name = $row['state_name'];  
$state_id = $row['state_id'];  

$optionList .= "<option value=". $city_id . ">". $city_name . ", " . $state_name . "</option>";               

    }  

// output 

echo "<select name=location>";  

echo $optionList;  

echo "</select>";  


echo '<form method = "get"
      action = "cityid5.php">';

echo '<input type = "submit"></form>';      

[jabi]

You are only passing $city_id as the location.

BOTH variables need to be passed if you want to use them in your WHERE statement on the processing page.

On your form page, create a new variable $newlocation as the value of your select option list:

$newlocation = $city_id.",".$state_id;

On the processing page, initialized your $newlocation, then explode the passed variable:

$location = "";
if(isset($POST['newlocation'])) {
$pieces = explode(",",$REQUEST['newlocation']);
$city_id = $pieces[0];
$state_id = $pieces[1];
}

You can then use the $city_id and $state_id in your WHERE clause.

Is there a reason for using the GET method instead of POST?

[dartcol]

On the page which is referred to by the action in your form check to see if the form has been submitted by using:

if (isset($_POST['submit']))
     {
      // insert your action here
     }

This means back in your form put a name to your submit button:

<input type=submit name=submit value=submit>

This should work. Another thing, it's easier to use $_POST[''] in this case.

[sylunt1]

Thanks for the info. Why is POST easier than GET? I thought they were basically the same?

[dartcol]

My thoughts:

I'd rename your tables to the following:
bm_city
bm_city_id
bm_city_name
bm_city_stateid

bm_state
bm_state_id
bm_state_name

Then use extract() so you can use the col names in your tables as variables.
SELECT only the variables you need to echo on the page or pass as variables to another page.

// form.php - you page with the form

<form method=POST action=cityid5.php>
<select name=location>

<?php
$sql = "SELECT bm_city_name, bm_state_name
		WHERE bm_city_stateid = bm_state_id
		ORDER BY bm_city_name";

$result = mysql_query($sql);

while($row = mysql_fetch_array($result))
	{
	extract($row);
	echo '<option value='.$bm_city_name'>'.$bm_city_name.', '.$bm_state_name.'</option>';
	}
?>

</select>
<input type=submit name=submit value=submit>
</form>';


// cityid5.php - your form processing page

<?php
if(isset($_POST['submit']))
	{
	$sql = "SELECT bm_city_id, bm_city_name, bm_state_name
			FROM bm_city, bm_state
			WHERE bm_city_name = '".$_POST['location']."' 
				AND bm_state_id = bm_city_id";

$result = mysql_query($sql);

while($row = mysql_fetch_array($result))
	{
	extract($row);
	echo $bm_city_name.','.$bm_state_name.' - '.$bm_city_id.'<br><br>';
	}
}

?>

Differences between GET and POST? Do a google. Here's a link.

This should work if you rename your tables. I do it this way as it's easier to keep track of what tables you're
using where. Downside is that table names can get a bit long.