PHP Conference Japan 2024

mysqli_stmt::fetch

mysqli_stmt_fetch

(PHP 5, PHP 7, PHP 8)

mysqli_stmt::fetch -- mysqli_stmt_fetchObtiene los resultados de una sentencia preparadas en las variables vinculadas

Descripción

Estilo orientado a objetos

mysqli_stmt::fetch(): bool

Estilo por procedimientos

mysqli_stmt_fetch(mysqli_stmt $stmt): bool

Obtiene los resultados de una sentencia preparadas en las variables vinculadas mediante mysqli_stmt_bind_result().

Nota:

Observe que todas las columnas deben estar vinculadas por la aplicación antes de llamar a mysqli_stmt_fetch().

Nota:

Los datos son transferidos sin almacenarlos en buffer sin llamar a mysqli_stmt_store_result(), la cual puede disminuir el rendimiento (pero reduce el coste de memoria).

Parámetros

stmt

Sólo estilo por procediminetos: Un identificador de declaraciones devuelto por mysqli_stmt_init().

Valores devueltos

Valores devueltos
Valor Descripción
true Éxito. Los datos se han obtenido
false Ocurrió un error
null No existen más filas/datos u ocurrió un truncamiento de los datos

Ejemplos

Ejemplo #1 Estilo orientado a objetos

<?php
$mysqli
= new mysqli("localhost", "mi_usuario", "mi_contraseña", "world");

/* comprobar la conexión */
if (mysqli_connect_errno()) {
printf("Falló la conexión: %s\n", mysqli_connect_error());
exit();
}

$consulta = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 150,5";

if (
$sentencia = $mysqli->prepare($consulta)) {

/* ejecutar la sentencia */
$sentencia->execute();

/* vincular las variables de resultados */
$sentencia->bind_result($nombre, $código);

/* obtener los valores */
while ($sentencia->fetch()) {
printf ("%s (%s)\n", $nombre, $código);
}

/* cerrar la sentencia */
$sentencia->close();
}

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

Ejemplo #2 Estilo por procedimientos

<?php
$enlace
= mysqli_connect("localhost", "mi_usuario", "mi_contraseña", "world");

/* comprobar la conexión */
if (mysqli_connect_errno()) {
printf("Falló la conexión: %s\n", mysqli_connect_error());
exit();
}

$consulta = "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 150,5";

if (
$sentencia = mysqli_prepare($link, $consulta)) {

/* ejecutar la sentencia */
mysqli_stmt_execute($sentencia);

/* vincular las variables de resultados */
mysqli_stmt_bind_result($sentencia, $nombre, $código);

/* obtener los valores */
while (mysqli_stmt_fetch($sentencia)) {
printf ("%s (%s)\n", $nombre, $código);
}

/* cerrar la sentencia */
mysqli_stmt_close($sentencia);
}

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

El resultado de los ejemplos sería:

Rockford (USA)
Tallahassee (USA)
Salinas (USA)
Santa Clarita (USA)
Springfield (USA)

Ver también

add a note

User Contributed Notes 5 notes

up
19
Bruce Martin
12 years ago
I was trying to use a generic select * from table statment and have the results returned in an array. I finally came up with this solution, others have similar solutions, but they where not working for me.
<?php
//Snip use normal methods to get to this point
$stmt->execute();
$metaResults = $stmt->result_metadata();
$fields = $metaResults->fetch_fields();
$statementParams='';
//build the bind_results statement dynamically so I can get the results in an array
foreach($fields as $field){
if(empty(
$statementParams)){
$statementParams.="\$column['".$field->name."']";
}else{
$statementParams.=", \$column['".$field->name."']";
}
}
$statment="\$stmt->bind_result($statementParams);";
eval(
$statment);
while(
$stmt->fetch()){
//Now the data is contained in the assoc array $column. Useful if you need to do a foreach, or
//if your lazy and didn't want to write out each param to bind.
}
// Continue on as usual.
?>
up
6
dan dot latter at gmail dot com
17 years ago
The following function taken from PHP Cookbook 2, returns an associative array of a row in the resultset, place in while loop to iterate through whole result set.

<?php
public function fetchArray () {
$data = mysqli_stmt_result_metadata($this->stmt);
$fields = array();
$out = array();

$fields[0] = &$this->stmt;
$count = 1;

while(
$field = mysqli_fetch_field($data)) {
$fields[$count] = &$out[$field->name];
$count++;
}

call_user_func_array(mysqli_stmt_bind_result, $fields);
mysqli_stmt_fetch($this->stmt);
return (
count($out) == 0) ? false : $out;

}
?>
up
1
piedone at pyrocenter dot hu
16 years ago
I tried the mentioned stmt_bind_assoc() function, but somehow, very strangely it doesn't allow the values to be written in an array! In the while loop, the row is fetched correctly, but if I write $array[] = $row;, the array will be filled up with the last element of the dataset... Unfortunately I couldn't find a solution.
up
3
Lyndon
16 years ago
This function uses the same idea as the last, but instead binds the fields to a given array.
<?php
function stmt_bind_assoc (&$stmt, &$out) {
$data = mysqli_stmt_result_metadata($stmt);
$fields = array();
$out = array();

$fields[0] = $stmt;
$count = 1;

while(
$field = mysqli_fetch_field($data)) {
$fields[$count] = &$out[$field->name];
$count++;
}
call_user_func_array(mysqli_stmt_bind_result, $fields);
}

// example

$stmt = $mysqli->prepare("SELECT name, userid FROM somewhere");
$stmt->execute();

$row = array();
stmt_bind_assoc($stmt, $row);

// loop through all result rows
while ($stmt->fetch()) {
print_r($row);
}
?>
up
2
andrey at php dot net
19 years ago
IMPORTANT note: Be careful when you use this function with big result sets or with BLOB/TEXT columns. When one or more columns are of type (MEDIUM|LONG)(BLOB|TEXT) and ::store_result() was not called mysqli_stmt_fetch() will try to allocate at least 16MB for every such column. It _doesn't_ matter that the longest value in the result set is for example 30 bytes, 16MB will be allocated. Therefore it is not the best idea ot use binding of parameters whenever fetching big data. Why? Because once the data is in the mysql result set stored in memory and then second time in the PHP variable.
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