PHP mysqli_fetch_field() 函数

返回结果集中下一字段（列），然后输出每个字段名称、表格和最大长度：

<?php 
// 假定数据库用户名：root，密码：123456，数据库：RUNOOB 
$con=mysqli_connect("localhost","root","123456","RUNOOB"); 
if (mysqli_connect_errno($con)) 
{ 
    echo "连接 MySQL 失败: " . mysqli_connect_error(); 
} 

$sql="SELECT name,url FROM websites ORDER BY alexa";


if ($result=mysqli_query($con,$sql))
{
    // 获取所有列的字段信息
    while ($fieldinfo = mysqli_fetch_field($result)) {

        printf("字段名:     %s\n", $fieldinfo->name);
        echo "<br>";
        printf("数据表:    %s\n", $fieldinfo->table);
        echo "<br>";
        printf("最大长度: %d\n", $fieldinfo->max_length);
        echo "<br>";
    }
    // 释放结果集
    mysqli_free_result($result);
}

mysqli_close($con);
?>