PHP/mySQL POST problem

[PHPorbust]

Getting an intermittent error...ughh challenging

 

Overview:  I am trying to use a drop down menu populated from a mySql database.  Once the choice is selected it redirects to a php index page that uses if/else to redirect the page.  If it works correctly the redirect is back to the original page but now contains the POST ID associated with the user's choice which goes to another mySQL query and returns the echo'd results.  Problem is, sometimes this works and sometimes I get an error. It always works the first time.  When it does error and I echo the ID, it is blank.  I can reselect the same choice or a different one and sometimes it works, sometimes not. Any help would be appreciated.  IE

 

Error:Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /html/includes/search.php on line 

 

search.php:

<?php

require("connect.php");

 

//extract data mySQL

$extract = mysql_query("SELECT * FROM business ORDER BY id ASC");

 

echo "<form action ='index.php?page=search' method='POST'>";

echo "<select name='id'>";

 

while ($row = mysql_fetch_assoc($extract))

{

$id = $row['id'];

$grocery = $row[‘grocery'];

echo "<option value ='$id'>$grocery</option>";

}

 

echo "</select>";

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

?>

 

<?php

 

//extract data mySQL

$q2 = "SELECT * FROM business WHERE ID = $_POST[id]";

$extract2 = mysql_query($q2);

$result2 = mysql_fetch_array($extract2);

$groc2 = $result2[‘grocery'];

$fru2 = $result2[‘fruit'];

?>

 

Here is the php index page that directs:

 

?php

include("includes/header.html");

include("includes/navbar.html");

 

if($_GET['page'] == "stores"){

 

include("includes/stores.php");

 

}else if($_GET['page'] == "search"){

 

include("includes/search.php");

 

}else if($_GET['page'] == "toys"){

 

include("includes/toys.html");

 

}else{

 

include("includes/home.html");

}

 

include("includes/footer.html");

?>

[Pikachu2000]

The error indicates a failed query. I'd start by adding some debugging code to the query that's producing the error.

 

$q2 = "SELECT * FROM business WHERE ID = $_POST[id]";
$extract2 = mysql_query($q2) or die( '<br>Query: ' . $q2 . '<br>Produced error: ' mysql_error() . '<br>');

[PHPorbust]

$extract2 = mysql_query($q2) or die('<br>Query:'.$q2.'<br>Produced error:'mysql_error()'); =

Parse error: syntax error, unexpected T_STRING in /***/search.php on line 

 

[PHPorbust]

I do get this error:

 

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

 

when I use:

$extract2 = mysql_query($q2) or  die(mysql_error());

[Pikachu2000]

I missed a concatenation "dot"

' . mysql_error()

^ there

[PHPorbust]

$extract2 = mysql_query($q2) or die('<br>Query:'.$q2.'<br>Produced error:'.mysql_error()'); =

Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING in /***/search.php on line  +2

 

[Pikachu2000]

You've omitted the last <br>, but left an extra ' between the last 2 parentheses.

[PHPorbust]

Here you go....

 

Query: SELECT * FROM business WHERE ID =

Produced error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1

 

[Pikachu2000]

It's exactly what I expected; I just don't see anything in the code that would cause it to happen. Are you getting any other errors at all?

[PHPorbust]

What did you expect exactly? 

 

No other errors at all that I can see .

 

 

 

 

[Pikachu2000]

I expected to see a blank spot at the end of the query, and that's what was there . . . Hmmmm. There's no pattern at all as to when this occurs, huh?