PHP 中 foreach 循环，出现一个问题，提取数据时总是缺一条数据？ [ 2.0 版本 ]

<?php

$sskkMap = array('商品代码'=>'A','商品'=>'B','价格'=>'C');

$kkssMap = array('aasd'=>'A','sxfd'=>'B','dxdx'=>'C');

$objPHPExcel = new PHPExcel();

$objPHPExcel->getProperties()->setCreator("Maarten Balliauw"); 

$sql = "select * from CARCAR where '1' LIMIT 0 ,500"; //完成

$lists = $db->select($sql); 

$i = 0 ;

foreach($lists as $record) 

{ 

$i++; 

if($i == 1) //$i==0,数据首条就出现了。但是表格首行没了

foreach($sskkMap as $k =>$col) //表格首行

{

$objPHPExcel->setActiveSheetIndex()->setCellValue($col.$i, $k); 

}

else

foreach($kkssMap as $k =>$col) //表格第二行起。这里总是缺一条数据没提取出来。。

{ //好像就是数据的首条。

$objPHPExcel->setActiveSheetIndex()->setCellValue($col.$i, $record[$k]); 

}

} 

if(!empty($lists))

{

$objPHPExcel->getActiveSheet()->setTitle('Simple'); 

$objPHPExcel->setActiveSheetIndex(0);

$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5'); 

$objWriter->save('php://output');

}

?>