mysqli_stmt::$num_rows

mysqli_stmt::num_rows

mysqli_stmt_num_rows

(PHP 5, PHP 7, PHP 8)

mysqli_stmt::$num_rows -- mysqli_stmt::num_rows -- mysqli_stmt_num_rows — Returns the number of rows fetched from the server

说明

面向对象风格

int|string $mysqli_stmt->num_rows;

public mysqli_stmt::num_rows(): int|string

过程化风格

mysqli_stmt_num_rows(mysqli_stmt $statement): int|string

Returns the number of rows buffered in the statement. This function will only work after mysqli_stmt_store_result() is called to buffer the entire result set in the statement handle.

This function returns 0 unless all rows have been fetched from the server.

参数

statement: 仅以过程化样式：由 mysqli_stmt_init() 返回的 mysqli_stmt 对象。

返回值

An int representing the number of buffered rows. Returns 0 in unbuffered mode unless all rows have been fetched from the server.

注意:
If the number of rows is greater than PHP_INT_MAX, the number will be returned as a string.

范例

示例 #1 面向对象风格


<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

$query = "SELECT Name, CountryCode FROM City ORDER BY Name LIMIT 20";
$stmt = $mysqli->prepare($query);
$stmt->execute();

/* store the result in an internal buffer */
$stmt->store_result();

printf("Number of rows: %d.\n", $stmt->num_rows);

示例 #2 过程化风格


<?php

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");

$query = "SELECT Name, CountryCode FROM City ORDER BY Name LIMIT 20";
$stmt = mysqli_prepare($link, $query);
mysqli_stmt_execute($stmt);

/* store the result in an internal buffer */
mysqli_stmt_store_result($stmt);

printf("Number of rows: %d.\n", mysqli_stmt_num_rows($stmt));

以上例程会输出：

Number of rows: 20.

参见

mysqli_stmt_store_result() - Stores a result set in an internal buffer
mysqli_stmt_affected_rows() - Returns the total number of rows changed, deleted, inserted, or matched by the last statement executed
mysqli_prepare() - 准备执行一个 SQL 语句

add a note

User Contributed Notes 1 note

down

Typer85 at gmail dot com ¶

15 years ago


Please be advised, for people who sometimes miss to read this important Manual entry for this function:


If you do not use mysqli_stmt_store_result( ), and immediatley call this function after executing a prepared statement, this function will usually return 0 as it has no way to know how many rows are in the result set as the result set is not saved in memory yet.


mysqli_stmt_store_result( ) saves the result set in memory thus you can immedietly use this function after you both execute the statement AND save the result set.


If you do not save the result set but still want to use this function you have to actually loop through the result set one row at a time using mysqli_stmt_fetch( ) before using this function to determine the number of rows.


A thought though, if you want to determine the number of rows without storing the result set and after looping through it, why not just simply keep an internal counter in your loop every time a row is fetched and save the function call.


In short, this function is only really useful if you save the result set and want to determine the number of rows before looping through it, otherwise you can pretty much recreate its use like I suggested.

add a note

官方地址：https://www.php.net/manual/en/mysqli-stmt.num-rows.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络数据库 JAVA 面试 NoSQL C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 ADORecordSet对象 adodb手册 opcache预加载 Composer的Packagist资源 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet PHP json解析（json_decode）页面工具 mysql面试题 [原创]诡异的php-fpm超时问题 php中几种注释规范纯php实现DES以及TripleDES加密算法 php 修改图片大小支持php7的性能采集扩展 PHP mkdir()写出来的权限与mode值不符合

略微加速

PHP官方手册 - 互联网笔记

mysqli_stmt::$num_rows

mysqli_stmt::num_rows

mysqli_stmt_num_rows

说明

参数

返回值

范例

参见

User Contributed Notes 1 note