使用php从mysql的html数据中下拉列表

Question

我有一个 HTML 下拉列表，其中的内容需要使用 PHP 从我的 MySQL 数据库加载。

我尝试了以下方法；但没有选项正在加载。

<strong> Select Data </strong> 
<select name="data1"> 
     <option value=""> NONE </option> 
<?php

$dd_res=mysql_query("Select relation FROM relation_names");
while($r=mysql_fetch_row($dd_res))
{ 
     echo "<option value='$r[0]'> $r[0] </option>";
}
?>
</select>

我也试过这样：

$q="SELECT DISTINCT *relation FROM relation_names";
$rs=mysql_query($q);
if($rs && mysql_num_rows($rs))
{
    while($rd=mysql_fetch_object($rs))
    { 
        echo("<option value='$rd->id'>$rd->name</option>");
    }
}

但我不知道为什么这些不起作用，请帮助我。

我根据评论尝试了下面的代码。 但选项名称没有显示。

Answer 1

<strong> Select Data </strong> 
<select name="data1"> 
<option value=""> NONE </option> 
<?php
// Mysql db connection
$con=mysqli_connect("localhost","my_user","my_password","my_db");

// Check connection
if (mysqli_connect_errno())
{
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// Perform queries 
$rs = mysqli_query($con,"SELECT DISTINCT relation FROM relation_names");
if($rs && mysqli_num_rows($rs))
{
     while($rd=mysqli_fetch_object($rs))
     { 
         echo("<option value='$rd->id'>$rd->relation</option>");
     }
}
mysqli_close($con);
?>
</select>

Answer 2

使用mysqli_query() 或mysql_query()。因为mysql_query() 扩展在 PHP 5.5.0 中被弃用，在 PHP 7.0.0 中被移除。

<strong> Select Data </strong> 
<select name="data1"> 
    <option value=""> NONE </option> 
<?php
    // Mysql db connection
    $con=mysqli_connect("localhost","my_user","my_password","my_db");

    // Check connection
    if (mysqli_connect_errno())
    {
        echo "Failed to connect to MySQL: " . mysqli_connect_error();
    }

    // Perform queries 
    $rs = mysqli_query($con,"SELECT DISTINCT relation FROM relation_names");
    if($rs && mysqli_num_rows($rs))
    {
         while($rd=mysqli_fetch_object($rs))
         { 
             echo("<option value='$rd->id'>$rd->name</option>");
         }
    }
    mysqli_close($con);
?>
</select>

参考下面mysqli扩展

mysqli_connect()

mysqli_connect_errno()

mysqli_connect_error()

mysqli_query()

mysqli_num_rows()

mysqli_fetch_object()