PHP 中的 mysqli num fields函数

mysqli num fields - 语法

int mysqli_num_fields ( mysqli_result $result );

它返回输出集中的字段数。

mysqli num fields - 返回值

它返回输出集中的字段数。

mysqli num fields - 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();
   }
   
   $sql="SELECT name FROM emp";
   
   if ($result=mysqli_query($connection_mysql,$sql)){
      $fieldcount=mysqli_num_fields($result);
      
      print $fieldcount;
      mysqli_free_result($result);
   }
   mysqli_close($connection_mysql);
?>