PHP mysqli_num_fields () function

PHP MySQLi Reference Manual

Return result set fields (columns) Quantity:

<?php 
// 假定数据库用户名：root，密码：123456，数据库：w3big 
$con=mysqli_connect("localhost","root","123456","w3big"); 
if (mysqli_connect_errno($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))
{
	// 返回结果集中的字段数
	$fieldcount=mysqli_num_fields($result);
	printf("结果集中有 %d 个字段。",$fieldcount);
	// 释放结果集
	mysqli_free_result($result);
}


mysqli_close($con);
?>

Definition and Usage

mysqli_num_fields () function returns the result set field (column) number.

grammar

technical details