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mysqli::$affected_rows

mysqli_affected_rows

(PHP 5, PHP 7, PHP 8)

mysqli::$affected_rows -- mysqli_affected_rows — Получает число строк, затронутых предыдущей операцией MySQL

Описание

Объектно-ориентированный стиль

int|string $mysqli->affected_rows;

Процедурный стиль

mysqli_affected_rows(mysqli $mysql): int|string

Возвращает число строк, затронутых последним запросом INSERT, UPDATE, REPLACE или DELETE. Работает аналогично mysqli_num_rows() для выражений SELECT.

Список параметров

mysql: Только для процедурного стиля: объект mysqli, который вернула функция mysqli_connect() или функция mysqli_init().

Возвращаемые значения

Целое число, большее нуля, означает количество затронутых или полученных строк. Ноль означает, что записи для оператора UPDATE не обновлялись, ни одна строка не соответствовала выражению WHERE в запросе или что ни один запрос ещё не был выполнен. -1 означает, что во время выполнения запроса произошла ошибка или что mysqli_affected_rows() была вызвана для небуферизованного запроса SELECT.

Замечание:
Если число затронутых строк больше чем максимальное значение целого числа (PHP_INT_MAX), то число затронутых строк будет возвращено в виде строки.

Примеры

Пример #1 Пример использования $mysqli->affected_rows

Объектно-ориентированный стиль

<?php

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

/* Добавление строк */
$mysqli->query("CREATE TABLE Language SELECT * from CountryLanguage");
printf("Затронутые строки (INSERT): %d\n", $mysqli->affected_rows);

$mysqli->query("ALTER TABLE Language ADD Status int default 0");

/* Обновление строк */
$mysqli->query("UPDATE Language SET Status=1 WHERE Percentage > 50");
printf("Затронутые строки (UPDATE): %d\n", $mysqli->affected_rows);

/* Удаление строк */
$mysqli->query("DELETE FROM Language WHERE Percentage < 50");
printf("Затронутые строки (DELETE): %d\n", $mysqli->affected_rows);

/* Выборка всех строк */
$result = $mysqli->query("SELECT CountryCode FROM Language");
printf("Затронутые строки (SELECT): %d\n", $mysqli->affected_rows);

/* Удаление таблицы Language */
$mysqli->query("DROP TABLE Language");
?>

Процедурный стиль

<?php

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

/* Добавление строк */
mysqli_query($link, "CREATE TABLE Language SELECT * from CountryLanguage");
printf("Затронутые строки (INSERT): %d\n", mysqli_affected_rows($link));

mysqli_query($link, "ALTER TABLE Language ADD Status int default 0");

/* Обновление строк */
mysqli_query($link, "UPDATE Language SET Status=1 WHERE Percentage > 50");
printf("Затронутые строки (UPDATE): %d\n", mysqli_affected_rows($link));

/* Удаление строк */
mysqli_query($link, "DELETE FROM Language WHERE Percentage < 50");
printf("Затронутые строки (DELETE): %d\n", mysqli_affected_rows($link));

/* Выборка всех строк */
$result = mysqli_query($link, "SELECT CountryCode FROM Language");
printf("Затронутые строки (SELECT): %d\n", mysqli_affected_rows($link));

/* Удаление таблицы Language */
mysqli_query($link, "DROP TABLE Language");
?>

Результат выполнения приведённых примеров:

Затронутые строки (INSERT): 984
Затронутые строки (UPDATE): 168
Затронутые строки (DELETE): 815
Затронутые строки (SELECT): 169

Смотрите также

mysqli_num_rows() - Получает количество строк в наборе результатов
mysqli_info() - Извлекает информацию о последнем выполненном запросе

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User Contributed Notes 7 notes

down

Anonymous ¶

13 years ago


On "INSERT INTO ON DUPLICATE KEY UPDATE" queries, though one may expect affected_rows to return only 0 or 1 per row on successful queries, it may in fact return 2.

From Mysql manual: "With ON DUPLICATE KEY UPDATE, the affected-rows value per row is 1 if the row is inserted as a new row and 2 if an existing row is updated."

See: http://dev.mysql.com/doc/refman/5.0/en/insert-on-duplicate.html

Here's the sum breakdown _per row_:
+0: a row wasn't updated or inserted (likely because the row already existed, but no field values were actually changed during the UPDATE)
+1: a row was inserted
+2: a row was updated

down

Jacques Amar ¶

7 years ago


While using prepared statements, even if there is no result set (Like in an UPDATE or DELETE), you still need to store the results before affected_rows returns the actual number:

<?php
$del_stmt->execute();
$del_stmt->store_result();
$count = $del_stmt->affected_rows;
?>

Otherwise things will just be frustrating ..

down

Michael ¶

10 years ago


If you need to know specifically whether the WHERE condition of an UPDATE operation failed to match rows, or that simply no rows required updating you need to instead check mysqli::$info.

As this returns a string that requires parsing, you can use the following to convert the results into an associative array.

Object oriented style:

<?php
    preg_match_all ('/(\S[^:]+): (\d+)/', $mysqli->info, $matches); 
    $info = array_combine ($matches[1], $matches[2]);
?>

Procedural style:

<?php
    preg_match_all ('/(\S[^:]+): (\d+)/', mysqli_info ($link), $matches); 
    $info = array_combine ($matches[1], $matches[2]);
?>

You can then use the array to test for the different conditions

<?php
    if ($info ['Rows matched'] == 0) {
        echo "This operation did not match any rows.\n";
    } elseif ($info ['Changed'] == 0) {
        echo "This operation matched rows, but none required updating.\n";
    }

    if ($info ['Changed'] < $info ['Rows matched']) {
        echo ($info ['Rows matched'] - $info ['Changed'])." rows matched but were not changed.\n";
    }
?>

This approach can be used with any query that mysqli::$info supports (INSERT INTO, LOAD DATA, ALTER TABLE, and UPDATE), for other any queries it returns an empty array.

For any UPDATE operation the array returned will have the following elements:

Array
(
    [Rows matched] => 1
    [Changed] => 0
    [Warnings] => 0
)

down

-1

lucgommans.nl ¶

1 year ago


Under the hood, this calls into mysql_affected_rows (1). The MariaDB function ROW_COUNT() mentions (2) that it is the equivalent of that C API function. These two lines, SQL followed by PHP, should be equivalent:

SELECT ROW_COUNT();
$db->affected_rows;

I found this useful to double check things in an SQL prompt, to make sure affected_rows is reflecting what I expect (changed rows as opposed to matched rows in an update statement), which indeed it did.

1. https://github.com/php/php-src/blob/1521cafee29e23ca147ec777f3770a7ac46c6880/ext/mysqli/mysqli_api.c#L36-L49
2. https://mariadb.com/kb/en/row_count/

down

-7

fastest963 at gmail dot com ¶

10 years ago


empty($db->affected_rows) will return TRUE even if affected_rows is greater than 0. Manually check < 1 if you're looking for failure.

down

-11

anonymous ¶

9 years ago


This may seem obvious, but if you do an UPDATE with each of the values in your SET clause having the exact same value that is already in the table, then affected_rows returns 0.  For example:

<?php
    $mysqli = new mysqli($host, $usr, $pwd, $db, $port);
    $appointment_date = "2015-12-07";
    $sql = "update appointments set appointment_date = ? where appointment_id = 78";
    $stmt = $mysqli->prepare($sql);
    $stmt->bind_param("s",$appointment_date);
    $stmt->execute();
    echo $mysqli ->affected_rows . "<br>";
?>

This returns 1 the first time I run it after changing the value of the $appointment_date variable.  When I run it a second time (making no changes), it returns 0.  I also verified the same behavior without using prepared statements.

down

-16

oilpc at oilpc dot com ¶

15 years ago


For "INSERT" or "UPDATE" statement for modifying data contained in one row of one table I checked if number of affected rows equals 1 to determine success of the operation. It works fine both for errors and false value of WHERE condition (that might be generated according to specific application user acces privileges).
<?php
if ($mysqli->affected_rows==1){
    echo "success";
}
else {
    echo "fail";
}
?>

Checking if mysqli->affected_rows will equal -1 or not is not a good method of determining success of "INSERT IGNORE" statements. Example: Ignoring duplicate key errors while inserting some rows containing data provided by user only if they will match specified unique constraint causes returning of -1 value by mysqli->affected_rows even if rows were inserted. (checked on MySQL 5.0.85 linux and php 5.2.9-2 windows). However mysqli->sqlstate returns no error if statement was executed successfully.
<?php
if ($mysqli->affected_rows!=-1){
    echo "success";// for "INSERT IGNORE" statements will not occur if there were any duplicate key errors ignored during execution of the query
}
else {
    echo "fail";// "INSERT IGNORE" statements causing any duplicate key errors (however ignored) lead to mysqli->affected_rows equal -1
}

// Example below works for "INSERT IGNORE" stattements, too
if ($mysqli->sqlstate=="00000"){
    echo "success";
}
else {
    echo "fail";
}
?>

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