php获得sybase数据库内容的有关问题

public static function Connect()<br />
 {<br />
 $obj =new DB();<br />
 $conn=$obj->Connection=sybase_connect(SERVER_NAME, USER, PASSWORD) ; // 连接数据库<br />
 if(!$conn){<br />
 echo '数据库连接错误...';<br />
 exit(0);<br />
 }<br />
 sybase_select_db(DATABASE_NAME);<br />
     return $obj;  <br />
 }<br />
 //初始化页面时查询最近一个月的销售记录<br />
 public function QueryLastMonth(){<br />
 $start_date=str_replace('-','',date('Y-m-d',strtotime('-1 month')));<br />
 $end_date=str_replace('-','',date('Y-m-d',time()));<br />
 $sql_str="select cusno as shopcode,u2.nos as salesid,u2.colthno as goodsid,u2.endprice as price,u2.nb as goodscount from u2sale u1,u2saleb u2 where u1.outdate>=";<br />
$sql=$sql_str ."'".$start_date."' and u1.outdate<='".$end_date."' and u1.nos=u2.nos and u1.nb>0 and u2.endprice>0;";<br />
<br />
  //echo $sql;<br />
 // sybase_query("set rowcount " . 20) ; // 执行SQL命令，设置返回记录行数<br />
   $result = sybase_query($sql) ; // 执行SQL命令，检索数据库<br />
   echo "---".$result;<br />
   while($row = sybase_fetch_assoc($result)) <br />
   { <br />
  // echo 'xxx';<br />
   echo $row["shopcode"] . "---" . $row["salesid"] . "---" . $row["goodscount"] . "\n" ;<br />
    }<br />
	<br />
	sybase_close($conn);<br />
 }