MySQL Error: 1064 the ambiguous error

<?php

session_start();

// $username = $_SESSION['username'];

if (empty($_SESSION['username'])) {
    session_destroy();
    header('location:login.php');
}

/*
 * Script:    DataTables server-side script for PHP and MySQL
 * Copyright: 2010 - Allan Jardine, 2012 - Chris Wright
 * License:   GPL v2 or BSD (3-point)
 */

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Easy set variables
 */

/* Array of database columns which should be read and sent back to DataTables. Use a space where
 * you want to insert a non-database field (for example a counter or static image)
 */
$aColumns = array('id', 'date', 'wo_number', 'sheet_no', 'step', 'reg_no', 'start_time', 'finish_time', 'status_shift', 'status_working', 'personnel_name', 'title_WO');

/* Indexed column (used for fast and accurate table cardinality) */
$sIndexColumn = "id";

/* DB table to use */
$sTable = "daily_activity_control_card-man";

/* Database connection information */
// $gaSql['user']       = "root";
// $gaSql['password']   = "";
// $gaSql['db']         = "hidden";
//$gaSql['server']     = "localhost";

$gaSql['user'] = "hidden";
$gaSql['password'] = "hidden";
$gaSql['db'] = "hidden";
$gaSql['server'] = "localhost";


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * If you just want to use the basic configuration for DataTables with PHP server-side, there is
 * no need to edit below this line
 */

/*
 * Local functions
 */
function fatal_error($sErrorMessage = '')
{
    header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error');
    die($sErrorMessage);
}


/*
 * MySQL connection
 */
if (!$gaSql['link'] = mysql_pconnect($gaSql['server'], $gaSql['user'], $gaSql['password'])) {
    fatal_error('Could not open connection to server');
}

if (!mysql_select_db($gaSql['db'], $gaSql['link'])) {
    fatal_error('Could not select database ');
}


/*
 * Paging
 */
$sLimit = "";
if (isset($_GET['iDisplayStart']) && $_GET['iDisplayLength'] != '-1') {
    $sLimit = "LIMIT " . intval($_GET['iDisplayStart']) . ", " .
        intval($_GET['iDisplayLength']);
}


/*
 * Ordering
 */
$sOrder = "";
if (isset($_GET['iSortCol_0'])) {
    $sOrder = "ORDER BY  ";
    for ($i = 0; $i < intval($_GET['iSortingCols']); $i++) {
        if ($_GET['bSortable_' . intval($_GET['iSortCol_' . $i])] == "true") {
            $sOrder .= $aColumns[intval($_GET['iSortCol_' . $i])] . "
                    " . ($_GET['sSortDir_' . $i] === 'asc' ? 'asc' : 'desc') . ", ";
        }
    }

    $sOrder = substr_replace($sOrder, "", -2);
    if ($sOrder == "ORDER BY") {
        $sOrder = "";
    }
}


/*
 * Filtering
 * NOTE this does not match the built-in DataTables filtering which does it
 * word by word on any field. It's possible to do here, but concerned about efficiency
 * on very large tables, and MySQL's regex functionality is very limited
 */
$sWhere = "";
if (isset($_GET['sSearch']) && $_GET['sSearch'] != "") {
    $sWhere = "WHERE (";
    for ($i = 0; $i < count($aColumns); $i++) {
        if (isset($_GET['bSearchable_' . $i]) && $_GET['bSearchable_' . $i] == "true") {
            $sWhere .= $aColumns[$i] . " LIKE '%" . mysql_real_escape_string($_GET['sSearch']) . "%' OR ";
        }
    }
    $sWhere = substr_replace($sWhere, "", -3);
    $sWhere .= ')';
}

/* Individual column filtering */
for ($i = 0; $i < count($aColumns); $i++) {
    if (isset($_GET['bSearchable_' . $i]) && $_GET['bSearchable_' . $i] == "true" && $_GET['sSearch_' . $i] != '') {
        if ($sWhere == "") {
            $sWhere = "WHERE ";
        } else {
            $sWhere .= " AND ";
        }
        $sWhere .= $aColumns[$i] . " LIKE '%" . mysql_real_escape_string($_GET['sSearch_' . $i]) . "%' ";
    }
}

/*
 * SQL queries
 * Get data to display
 */


$sQuery = " SELECT a.*, b.personnel_name, c.title_WO FROM `daily_activity_control_card-man` as a INNER JOIN `personnel_master_data` as b ON a.reg_no = b.reg_no INNER JOIN `work_order` as c on a.wo_number = c.wo_number
        $sOrder
        $sLimit
    ";
$rResult = mysql_query($sQuery, $gaSql['link']) or fatal_error('MySQL Error: ' . mysql_errno());

/* Data set length after filtering */
$sQuery = "
        SELECT FOUND_ROWS()
    ";
$rResultFilterTotal = mysql_query($sQuery, $gaSql['link']) or fatal_error('MySQL Error: ' . mysql_errno());
$aResultFilterTotal = mysql_fetch_array($rResultFilterTotal);
$iFilteredTotal = $aResultFilterTotal[0];

/* Total data set length */
$sQuery = "
        SELECT COUNT(" . $sIndexColumn . ")
        FROM   $sTable
    ";
$rResultTotal = mysql_query($sQuery, $gaSql['link']) or fatal_error('MySQL Error: ' . mysql_errno());
$aResultTotal = mysql_fetch_array($rResultTotal);
$iTotal = $aResultTotal[0];


/*
 * Output
 */
/*
$output = array(
    "sEcho" => intval($_GET['sEcho']),
    "iTotalRecords" => $iTotal,
    "iTotalDisplayRecords" => $iFilteredTotal,
    "aaData" => array()
);
*/

while ($aRow = mysql_fetch_array($rResult)) {
    $row = array();
    for ($i = 0; $i < count($aColumns); $i++) {
        if ($aColumns[$i] == "version") {
            /* Special output formatting for 'version' column */
            $row[] = ($aRow[$aColumns[$i]] == "0") ? '-' : $aRow[$aColumns[$i]];
        } else if ($aColumns[$i] != ' ') {
            /* General output */
            $row[] = $aRow[$aColumns[$i]];
        }
    }
    $output['aaData'][] = $row;
}

echo json_encode($output);
?>