PHP 中的 mysqli num rows函数

mysqli num rows - 语法

int mysqli_num_rows ( mysqli_result $result );

它返回输出集中的行数

mysqli num rows - 返回值

它返回输出集中的行数.

mysqli num rows - 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 Lastname FROM Persons";
   
   if ($result=mysqli_query($connection_mysql,$sql)){
      $rowcount=mysqli_num_rows($result);
      
      printf("Result set has %d rows.\n",$rowcount);
      mysqli_free_result($result);
   }
   mysqli_close($connection_mysql);
?>