mysqli_fetch_lengths() 函数返回结果集中的字段长度。
<?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)) { $row=mysqli_fetch_row($result); // 显示字段长度 foreach (mysqli_fetch_lengths($result) as $i=>$val) { printf("字段 %2d 长度为: %2d",$i+1,$val); echo "<br>"; } // 释放结果集 mysqli_free_result($result); } mysqli_close($con); ?>