略微加速

PHP官方手册 - 互联网笔记

PHP - Manual: mysqli_result::$num_rows

2024-11-14

mysqli_result::$num_rows

mysqli_num_rows

(PHP 5, PHP 7, PHP 8)

mysqli_result::$num_rows -- mysqli_num_rowsGets the number of rows in the result set

说明

面向对象风格

过程化风格

mysqli_num_rows(mysqli_result $result): int|string

Returns the number of rows in the result set.

The behaviour of mysqli_num_rows() depends on whether buffered or unbuffered result sets are being used. This function returns 0 for unbuffered result sets unless all rows have been fetched from the server.

参数

result

仅以过程化样式:由 mysqli_query()mysqli_store_result()mysqli_use_result()mysqli_stmt_get_result() 返回的 mysqli_result 对象。

返回值

An int representing the number of fetched 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");

$result $mysqli->query("SELECT Code, Name FROM Country ORDER BY Name");

/* Get the number of rows in the result set */
$row_cnt $result->num_rows;

printf("Result set has %d rows.\n"$row_cnt);

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");

$result mysqli_query($link"SELECT Code, Name FROM Country ORDER BY Name");

/* Get the number of rows in the result set */
$row_cnt mysqli_num_rows($result);

printf("Result set has %d rows.\n"$row_cnt);

以上例程会输出:

Result set has 239 rows.

注释

注意:

In contrast to the mysqli_stmt_num_rows() function, this function doesn't have object-oriented method variant. In the object-oriented style, use the getter property.

参见

add a noteadd a note

User Contributed Notes 3 notes

up
123
borisigna
10 years ago
If you have problems making work this num_rows, you have to declare ->store_result() first.

<?php
$mysqli
= new mysqli("localhost","root", "", "tables");

$query = $mysqli->prepare("SELECT * FROM table1");
$query->execute();
$query->store_result();

$rows = $query->num_rows;

echo
$rows;

// Return 4 for example
?>
up
2
min0u
5 years ago
This function doesn't work with LIMIT used jointly with SQL_CALC_FOUND_ROWS. If you want to obtain the total rows found you must do it manually, example:

<?php
public function errorList(int $limit=25,int $offset=0){
       
$errorList = array();
       
$result = $this->con->query("SELECT SQL_CALC_FOUND_ROWS id, erreur FROM Erreurs ORDER BY id DESC LIMIT $limit OFFSET $offset");
        while(
$row = $result->fetch_assoc()){
           
$errorList[] = new Erreur($row);
        }
       
$result->free();
       
// $foundRows = $result->num_rows; // 25
       
$foundRows = $this->con->query("SELECT FOUND_ROWS() as foundRows");
       
$this->foundRows = $foundRows->fetch_assoc(); // 178
       
return $errorList;
}
?>
up
-30
justso at inbox dot ru
6 years ago
in php 5.3.8 had unexpected troubles when checking for mysqli_result::$num_rows
If the result of the query is empty then var_dump of the result will be like this:
class mysqli_result#5 (5) {
  public $current_field => NULL
  public $field_count => NULL
  public $lengths => NULL
  public $num_rows => NULL
  public $type => NULL
}
but var_dump($result->num_rows) will give integer-typed zero instead of NULL:
int(0)

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

北京半月雨文化科技有限公司.版权所有 京ICP备12026184号-3