Using Session variable as WHERE predicate; am I approaching it wrongly? - php

Question

We would like to query our database and sample records based on a particular user's department.
Given the app design, the only way I know to do this is to filter the query by using dept's session variable.
The code below is not working.
Data gets returned if I comment out the session variable.
Nothing is getting retrieved with the session variable as filter.
Any ideas what I am doing wrong?
Is the session variable route the wrong approach?
Thanks in advance for help.
//Start your session
session_start();
// Connect to SQL Server database
include("../sqlConnect.php");
// Construct query
$loginName = $_GET['loginName'];
//Ok, let's grab user's dept from query
$sql = "SELECT ISNULL(dept,'NA') AS 'dept' FROM emp where ([userName]) = lower('$userName')"
$stmt = sqlsrv_query( $conn, $sql);
if( $stmt === false )
{
echo "Error in executing query.</br>";
die( print_r( sqlsrv_errors(), true));
}
$results = array();
while($row = sqlsrv_fetch_array($stmt,SQLSRV_FETCH_ASSOC)) {
array_push($results,$row);
$dept = $row['dept'];
}
//Store department in the session
$_SESSION['dept'] = $dept;
//Now extract records based on dept
$tsql ="SELECT
r.REQUESTID,
convert(char(10),r.[currDate],101),
r.[startedDBY],
e.[dept],
e.[WORKPHONE],
e.[EMAIL],
r.[DESCRIPTION],
r.[DETAILS],
r.[PROBLOCATION],
c.[COMMENTS]'
FROM EMPLOYEE e,REQUEST r,CUSTOMERCALL c
WHERE LOGINNAME='$loginName'
AND c.REQUESTID=r.requestid
AND e.dept = '" . $_SESSION['dept'] . "'
";
$stmt = sqlsrv_query( $conn, $tsql);
if( $stmt === false )
{
echo "Error in executing query.</br>";
die( print_r( sqlsrv_errors(), true));
}
$results = array();
while($row = sqlsrv_fetch_array($stmt,SQLSRV_FETCH_ASSOC)) {
array_push($results,$row);
}
echo json_encode($results);
// Free connection resources
sqlsrv_free_stmt( $stmt);
sqlsrv_close( $conn);