mysqli::$affected_rows

mysqli_affected_rows

(PHP 5)

mysqli::$affected_rows -- mysqli_affected_rowsObtiene el número de filas afectadas en la última operación MySQL

Descripción

Estilo orientado a objetos

Estilo por procedimientos

int mysqli_affected_rows ( mysqli $link )

Devuelve el numero de filas afectadas por la última consultaINSERT, UPDATE, REPLACE or DELETE.

Para instrucciones SELECT mysqli_affected_rows() es equivalente a mysqli_num_rows().

Parámetros

link

Sólo estilo por procediminetos: Un identificador de enlace devuelto por mysqli_connect() o mysqli_init()

Valores devueltos

Un entero mayor que cero indica el número de filas afectadas o recuperadas. El cero indica que no hay registros en una actualización con una sentencia UPDATE, que no hay filas que cumplan la cláusula WHERE de la sentencia o que ninguna consulta ha sido ejecutada todavía. -1 indica que la consulta devolvió un error.

Nota:

Si el número de filas afectadas es mayor de el máximo valor entero ( PHP_INT_MAX ), dicho número será devuelto como una cadena (string).

Ejemplos

Ejemplo #1 Ejemplo de $mysqli->affected_rows

Estilo orientado a objetos

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

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

/* Inserta filas */
$mysqli->query("CREATE TABLE Language SELECT * from CountryLanguage");
printf("Affected rows (INSERT): %d\n"$mysqli->affected_rows);

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

/* Actualiza filas */
$mysqli->query("UPDATE Language SET Status=1 WHERE Percentage > 50");
printf("Affected rows (UPDATE): %d\n"$mysqli->affected_rows);

/* Elimina filas */
$mysqli->query("DELETE FROM Language WHERE Percentage < 50");
printf("Affected rows (DELETE): %d\n"$mysqli->affected_rows);

/* Selecciona todas las filas */
$result $mysqli->query("SELECT CountryCode FROM Language");
printf("Affected rows (SELECT): %d\n"$mysqli->affected_rows);

$result->close();

/* Elimina la tabla "Language" */
$mysqli->query("DROP TABLE Language");

/* Cierra la conexión */
$mysqli->close();
?>

Estilo por procedimientos

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

if (!
$link) {
    
printf("Can't connect to localhost. Error: %s\n"mysqli_connect_error());
    exit();
}

/* Inserta filas */
mysqli_query($link"CREATE TABLE Language SELECT * from CountryLanguage");
printf("Affected rows (INSERT): %d\n"mysqli_affected_rows($link));

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

/* Actualiza filas */
mysqli_query($link"UPDATE Language SET Status=1 WHERE Percentage > 50");
printf("Affected rows (UPDATE): %d\n"mysqli_affected_rows($link));

/* Elimina filas */
mysqli_query($link"DELETE FROM Language WHERE Percentage < 50");
printf("Affected rows (DELETE): %d\n"mysqli_affected_rows($link));

/* Selecciona todas las filas */
$result mysqli_query($link"SELECT CountryCode FROM Language");
printf("Affected rows (SELECT): %d\n"mysqli_affected_rows($link));

mysqli_free_result($result);

/* Elimina la tabla "Language" */
mysqli_query($link"DROP TABLE Language");

/* Cierra la conexión */
mysqli_close($link);
?>

El resultado de los ejemplos serían:

Affected rows (INSERT): 984
Affected rows (UPDATE): 168
Affected rows (DELETE): 815
Affected rows (SELECT): 169

Ver también

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User Contributed Notes 5 notes

up
6
Anonymous
3 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
up
4
djnigelharkness at yahoo dot com
4 years ago
<?php
    $gHostName   
="localhost";   
   
$gUserName    ="root";
   
$gPassword    ="mypassword";
   
$gDBName     ="dbName";
   
$mysqli = new mysqli($gHostName, $gUserName, $gPassword,    
           
$gDBName);
   
   
$username="username";    $email="user@xxx.edu";
   
$password="3442f6e94a733237a3e844f0286b92f559bf794d";
   
   
//insert
//    $stmt = $mysqli->prepare("INSERT INTO j_user
       
(username,email,password) VALUES (?, ?, ?)");
//   
$stmt->bind_param('sss',$username, $email, $password);
//   
$stmt->execute();
//   
$stmt->close();

    //delete
//   
$stmt = $mysqli->prepare("DELETE FROM j_user WHERE
                        username
=?");
//   
$stmt->bind_param('s',$username);
//   
$stmt->execute();
//   
$stmt->close();

    //update
//   
$stmt = $mysqli->prepare("UPDATE j_user SET email=? WHERE
                        username
='wjw6349'");
//   
$stmt->bind_param('s',$email);
//   
$stmt->execute();
//   
$stmt->close();

    if (
$mysqli->connect_error){
        echo("
Connect failed: ".mysqli_connect_error()); exit();
    }

   
$querySelect = "SELECT * FROM j_user";
   
$resultSet = $mysqli->query($querySelect);
   
    if(
$resultSet->num_rows > 0){
        while(
$row = $resultSet->fetch_assoc()){
            foreach(
$row as $fieldValue){
               
$bigString .= "<em>$fieldValue</em><br />\n";
            }
           
$bigString .= "<hr />";
        }
       
$mysqli->close();
        echo
$bigString;
    }

    function __autoload(
$className) {
        require_once
$className.'.class.php';
    }
    //start the session and create it
    session_start();
   
$_SESSION['name'] = $_POST['username']."_".time();
    //encrypt the password   
    sha1(
$_POST['password']) == $password
    header("
Location:admin.php");
    //check if the session is set
    session_start();
    if (isset(
$_SESSION['name'])) { }
?>
up
3
ric at xpellshop dot com
3 years ago
"Zero indicates that no records where updated for an UPDATE statement, no rows matched the WHERE clause in the query or that no query has yet been executed."

what if i need to know which one of the three occurred? It's dumb that there is no distinction between the three.
up
1
fastest963 at gmail dot com
4 months ago
empty($db->affected_rows) will return TRUE even if affected_rows is greater than 0. Manually check < 1 if you're looking for failure.
up
-1
oilpc at oilpc dot com
4 years ago
For "INSERT" or "UPDATE" statement for modifying data contained in one row of one table I checked if number of affected rows equals 1 to determine success of the operation. It works fine both for errors and false value of WHERE condition (that might be generated according to specific application user acces privileges).
<?php
if ($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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