PHP 中的 mysqli field count函数

mysqli field count - 语法

mysqli_field_count(connection);

它返回最近查询的列数。

mysqli field count - 返回值

它返回输出集中的列数

mysqli field count - 示例

<?php
   $connection_mysql=mysqli_connect("localhost","user","password","db");
   
   if (mysqli_connect_errno($connection_mysql)){
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
   }
   
   mysqli_query($connection_mysql,"SELECT * FROM Persons");
   print(mysqli_field_count($connection_mysql));
   
   mysqli_close($connection_mysql);
?>