PHP mysqli use_result() 函数

定义和用法

use_result() / mysqli_use_result() 函数启动从上次执行的查询中检索结果集。

实例

例子 1 - 面向对象风格

启动从上次执行的查询中检索结果集：

<?php
$mysqli = new mysqli("localhost","my_user","my_password","my_db");

if ($mysqli -> connect_errno) {
  echo "Failed to connect to MySQL: " . $mysqli -> connect_error;
  exit();
}

$sql = "SELECT Lastname FROM Persons ORDER BY LastName;";
$sql .= "SELECT Country FROM Customers";

// 执行多查询
if ($mysqli -> multi_query($sql)) {
  do {
    // 存储第一个结果集
    if ($result = $mysqli -> use_result()) {
      while ($row = $result -> fetch_row()) {
        printf("%s\n", $row[0]);
      }
     $result -> close();
    }
    // 如果有更多的结果集，则打印分隔符
    if ($mysqli -> more_results()) {
      printf("-------------\n");
    }
     // 准备下一个结果集
  } while ($mysqli -> next_result());
}

$mysqli -> close();
?>

例子 2 - 过程式风格

启动从上次执行的查询中检索结果集：

<?php
$con = mysqli_connect("localhost","my_user","my_password","my_db");

if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  exit();
}

$sql = "SELECT Lastname FROM Persons ORDER BY LastName;";
$sql .= "SELECT Country FROM Customers";

// 执行多查询
if (mysqli_multi_query($con, $sql)) {
  do {
    // 存储第一个结果集
    if ($result = mysqli_use_result($con)) {
      while ($row = mysqli_fetch_row($result)) {
        printf("%s\n", $row[0]);
      }
      mysqli_free_result($result);
    }
    // 如果有更多的结果集，则打印分隔符
    if (mysqli_more_results($con)) {
      printf("-------------\n");
    }
     // 准备下一个结果集
  } while (mysqli_next_result($con));
}

mysqli_close($con);
?>

语法

面向对象风格：

$mysqli -> use_result()

过程式风格：

mysqli_use_result(connection)

技术细节