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HomeBackend DevelopmentPHP TutorialPHP函数内while 循环无效,该如何解决

PHP函数内while 循环无效
$conn = mysql_connect("localhost","root","root");//连接数据库,请填写你自己的用户名密码
mysql_select_db("hxxx");//选择MYSQL数据库 
mysql_query("set names utf-8");//设置为gb2312编码

function Cliebiao($mingcheng1,$mingcheng2){
$liebiao="";
$rows="";
$result = mysql_query("select mingcheng,daima from mingcheng where leixing='".$mingcheng1."'"); 
echo "$mingcheng1: ";
return $liebiao;
}
$mingchenga="类型名称";
$mingchengb="mingcheng";
Cliebiao($mingchenga,$mingchengb);
?>
符合条件的数据是存在的,而且不只一条,可程序执行后没有显示数据,只有“”类型名称: “”

请各位大师指点一下哪的问题


------解决思路----------------------
while($rows = mysql_fetch_row($result)){
 echo "";
 }
把里面的mysql_fetch_row变成mysql_fetch_array
------解决思路----------------------
奥才看到原来你还有一个Cliebiao函数呢。你那些链接数据库的代码函数里面引用不到的
------解决思路----------------------

<br /><br />global $conn;<br />$result = mysql_query("select mingcheng,daima from mingcheng where leixing='".$mingcheng1."'",$conn);<br /><br />

------解决思路----------------------
函数封装不是这样echo的吧。
------解决思路----------------------
<br /><?php<br />$conn = mysql_connect("localhost","root","root");//连接数据库,请填写你自己的用户名密码<br />mysql_select_db("hxxx");//选择MYSQL数据库 <br />mysql_query("set names utf-8");//设置为utf-8编码<br /><br />function Cliebiao($mingcheng1, $mingcheng2, $conn){<br />    $liebiao = "";<br />    $rows = "";<br />    $result = mysql_query("select mingcheng,daima from mingcheng where leixing='".$mingcheng1."'", $conn); <br />    $liebiao .= "$mingcheng1: <select name=$mingcheng2>";<br />    while($rows = mysql_fetch_array($result)){<br />        $liebiao .= "<option value=".$rows[1].">".$rows[0]."</option>";<br />    }<br />    $liebao .= "</select>";<br />    return $liebiao;<br />}<br />$mingchenga="类型名称";<br />$mingchengb="mingcheng";<br />echo Cliebiao($mingchenga, $mingchengb, $conn);<br />?><br />

1、请注意函数中尽量不要使用echo等输出类函数,这样会降低你的函数可重用性,你可以将函数中的内容return之后,将结果输出。
2、6楼说的对,你的句柄是在外面生成的内部无法获得,请里明确的标明你的句柄再使用mysql_query函数。
------解决思路----------------------

引用:
<br /><?php<br />$conn = mysql_connect("localhost","root","root");//连接数据库,请填写你自己的用户名密码<br />mysql_select_db("hxxx");//选择MYSQL数据库 <br />mysql_query("set names utf-8");//设置为utf-8编码<br /><br />function Cliebiao($mingcheng1, $mingcheng2, $conn){<br />    $liebiao = "";<br />    $rows = "";<br />    $result = mysql_query("select mingcheng,daima from mingcheng where leixing='".$mingcheng1."'", $conn); <br />    $liebiao .= "$mingcheng1: <select name=$mingcheng2>";<br />    while($rows = mysql_fetch_array($result)){<br />        $liebiao .= "<option value=".$rows[1].">".$rows[0]."</option>";<br />    }<br />    $liebiao .= "</select>";<br />    return $liebiao;<br />}<br />$mingchenga="类型名称";<br />$mingchengb="mingcheng";<br />echo Cliebiao($mingchenga, $mingchengb, $conn);<br />?><br />

1、请注意函数中尽量不要使用echo等输出类函数,这样会降低你的函数可重用性,你可以将函数中的内容return之后,将结果输出。
2、6楼说的对,你的句柄是在外面生成的内部无法获得,请里明确的标明你的句柄再使用mysql_query函数。

上边有个变量写错了,这个才是正确的
------解决思路----------------------
PHP函数内如何循环显示数据示例
//导入数据连接
if($_GET[mail_id]==true){
$query=mysql_query("update tb_mail_box set tb_mail_type=1 where tb_mail_id='$_GET[mail_id]'");
}
//数据库连接页面
 $conn=mysql_connect("localhost","root","root"); //连接数据库服务器
 mysql_select_db("db_forum",$conn); //连接指定的数据库
 mysql_query("set names gb2312"); //对数据库中的编码格式进行转换,避免出现中文乱码的问题
?>
//设置循环数据库表数据
$myrow=mysql_fetch_array($query);//循环数据
?>//codego.net/tags/4/1/
//显示表字段信息
//显示数据表中Email信息
//显示数据表中的某数量
//显示数据表中邮件名称
//显示邮件时间
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