附加两个sql表并将其导出为Excel文档php

Question

我在数据库deliverydata和deliverydata1中有两个表。我想附加它们并将结果导出为excel工作表。这是我的deliverydata表的sql到excel导出脚本。我应该添加什么代码来附加它们并将输出导出为excel工作表。两个表具有相同名称的相同列数。这是我的密码：

<?php


include 'db.php';
$SQL = "SELECT  WayFrom,WayTo,ConsignorName,ConsigneeName,PODStatus from deliverydata";
$header = '';
$result ='';
$exportData = mysql_query ($SQL ) or die ( "Sql error : " . mysql_error( ) );

$fields = mysql_num_fields ( $exportData );

for ( $i = 0; $i < $fields; $i++ )
{
    $header .= mysql_field_name( $exportData , $i ) . "\t";
}

while( $row = mysql_fetch_row( $exportData ) )
{
$line = '';
foreach( $row as $value )
{                                            
    if ( ( !isset( $value ) ) || ( $value == "" ) )
    {
        $value = "\t";
    }
    else
    {
        $value = str_replace( '"' , '""' , $value );
        $value = '"' . $value . '"' . "\t";
    }
    $line .= $value;
 }
 $result .= trim( $line ) . "\n";
 }
  $result = str_replace( "\r" , "" , $result );

if ( $result == "" )
{
  $result = "\nNo Record(s) Found!\n";                        
}

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=export.xls");
header("Pragma: no-cache");
header("Expires: 0");
print "$header\n$result";

?>