PHP mysqli_num_fields()Function
Returns the number of fields (columns) in the result set:
<?php
// 假定数据库用户名：root，密码：123456，数据库：EXAMPLE
$con=mysqli_connect("localhost","root","123456","EXAMPLE");
if (mysqli_connect_errno($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
The mysqli_num_fields() function returns the number of fields (columns) in a result set.
Syntax
mysqli_num_fields(result);
| Parameters | Description |
|---|---|
| result | Required. Specifies the result set identifier returned by mysqli_query(), mysqli_store_result(), or mysqli_use_result(). |
Technical Details
| Return value: | Returns the number of fields in the result set. |
|---|---|
| PHP Version: | 5+ |
PHP MySQLi Reference Manual Other Extensions