在我的数据表中选择语句

I have datatables setup and working displaying information from my table that I have set. However on one of my pages I want to set the datatable to only display data for a specific username. At the moment the datatable is displaying the whole table, how could I change the following code to only entries based on the session username.

The datatable code for sql queries is;

 $sQuery = "
    SELECT SQL_CALC_FOUND_ROWS ".str_replace(" , ", " ", implode(", ", $aColumns))."
    FROM   $sTable
    $sWhere
    $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];

When using an ordinary table I can display it correctly using;

$username = $_SESSION['username'];

$my_query="select * from loans where username = '$username' ";
$result= mysqli_query($connection, $my_query);

sWhere;

$sWhere = "";
if ( isset($_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])."%' ";
    }
}