php教程

mysqli_stmt::$affected_rows

mysqli_stmt_affected_rows

(PHP 5, PHP 7)

mysqli_stmt::$affected_rows -- mysqli_stmt_affected_rowsReturns the total number of rows changed, deleted, or inserted by the last executed statement

说明

面向对象风格

过程化风格

mysqli_stmt_affected_rows ( mysqli_stmt $stmt ) : int

Returns the number of rows affected by INSERT, UPDATE, or DELETE query.

This function only works with queries which update a table. In order to get the number of rows from a SELECT query, use mysqli_stmt_num_rows() instead.

参数

stmt

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

返回值

An integer greater than zero indicates the number of rows affected or retrieved. Zero indicates that no records where updated for an UPDATE/DELETE statement, no rows matched the WHERE clause in the query or that no query has yet been executed. -1 indicates that the query has returned an error. NULL indicates an invalid argument was supplied to the function.

Note:

If the number of affected rows is greater than maximal PHP int value, the number of affected rows will be returned as a string value.

范例

Example #1 面向对象风格

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

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

/* create temp table */
$mysqli->query("CREATE TEMPORARY TABLE myCountry LIKE Country");

$query "INSERT INTO myCountry SELECT * FROM Country WHERE Code LIKE ?";

/* prepare statement */
if ($stmt $mysqli->prepare($query)) {

    
/* Bind variable for placeholder */
    
$code 'A%';
    
$stmt->bind_param("s"$code);

    
/* execute statement */
    
$stmt->execute();

    
printf("rows inserted: %d\n"$stmt->affected_rows);

    
/* close statement */
    
$stmt->close();
}

/* close connection */
$mysqli->close();
?>

Example #2 过程化风格

<?php
$link 
mysqli_connect("localhost""my_user""my_password""world");

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

/* create temp table */
mysqli_query($link"CREATE TEMPORARY TABLE myCountry LIKE Country");

$query "INSERT INTO myCountry SELECT * FROM Country WHERE Code LIKE ?";

/* prepare statement */
if ($stmt mysqli_prepare($link$query)) {

    
/* Bind variable for placeholder */
    
$code 'A%';
    
mysqli_stmt_bind_param($stmt"s"$code);

    
/* execute statement */
    
mysqli_stmt_execute($stmt);

    
printf("rows inserted: %d\n"mysqli_stmt_affected_rows($stmt));

    
/* close statement */
    
mysqli_stmt_close($stmt);
}

/* close connection */
mysqli_close($link);
?>

以上例程会输出:

rows inserted: 17

参见

User Contributed Notes

gerbawn at 163 dot com 27-Jan-2015 06:47
I find should add $stmt->store_result() after $stmt->execute(), otherwise you can't get right results when use $stmt->affected_rows
Chuck 28-Apr-2007 10:51
I'm not sure whether or not this is the intended behavior, but I noticed through testing that if you were to use transactions and prepared statements together and you added a single record to a database using a prepared statement, but later rolled it back, mysqli_stmt_affected_rows will still return 1.
Carl Olsen 27-Dec-2005 10:34
It appears that an UPDATE prepared statement which contains the same data as that already in the database returns 0 for affected_rows.  I was expecting it to return 1, but it must be comparing the input values with the existing values and determining that no UPDATE has occurred.

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