PHP include within wordpress not connecting to an external database - php

Question

I am including a PHP page on a wordpres post with a wordpress plugin, the code on my included page is:
$conn=mysql_connect("localhost","username","pass");
mysql_select_db("dbname",$conn);
if(!function_exists("ContactLookup")) {
function ContactLookup($sequence) {
global $conn;
$sql="SELECT * from contacts where sequence = '".$sequence."' ";
$rs=mysql_query($sql,$conn) or die(mysql_error());
$result=mysql_fetch_array($rs);
return $result;
}
}
but its returning error:
Warning: mysql_query() expects parameter 2 to be resource, null given in index.php on line 93
line 93 = $rs=mysql_query($sql,$conn) or die(mysql_error());
Im not too sure why i receive this error because i have put $conn as a global variable in the PHP function and i have tested the database connection which works fine

Answer 1

rename the $conn variable to something else.
check this example:
$mysqlConn = null;
function ConnectToMysql() {
$mysqlConn=mysql_connect("localhost","username","pass") or die(mysql_error());
mysql_select_db("dbname",$mysqlConn) or die(mysql_error());
}
if(!function_exists("ContactLookup")) {
function ContactLookup($sequence) {
global $mysqlConn;
if(!$mysqlConn) ConnectToMysql(); // reconnect and reinit connection variable if somewhere it have been changed
$sql="SELECT * from contacts where sequence = '".$sequence."' ";
$rs=mysql_query($sql,$mysqlConn) or die(mysql_error());
$result=mysql_fetch_array($rs);
return $result;
}
}
P.S. I know my answer is not brilliant. I not fond of using mysql_* commands. but that's a quick fix.