mysqli_stmt::$num_rows

mysqli_stmt_num_rows

(PHP 5)

mysqli_stmt::$num_rows -- mysqli_stmt_num_rowsReturn the number of rows in statements result set

Beschreibung

Objektorientierter Stil

Prozeduraler Stil

int mysqli_stmt_num_rows ( mysqli_stmt $stmt )

Returns the number of rows in the result set. The use of mysqli_stmt_num_rows() depends on whether or not you used mysqli_stmt_store_result() to buffer the entire result set in the statement handle.

If you use mysqli_stmt_store_result(), mysqli_stmt_num_rows() may be called immediately.

Parameter-Liste

stmt

Nur bei prozeduralem Aufruf: ein von mysqli_stmt_init() zur├╝ckgegebenes Statementobjekt.

R├╝ckgabewerte

An integer representing the number of rows in result set.

Beispiele

Beispiel #1 Objektorientierter Stil

<?php
/* Open a connection */
$mysqli = new mysqli("localhost""my_user""my_password""world");

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

$query "SELECT Name, CountryCode FROM City ORDER BY Name LIMIT 20";
if (
$stmt $mysqli->prepare($query)) {

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

    
/* store result */
    
$stmt->store_result();

    
printf("Number of rows: %d.\n"$stmt->num_rows);

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

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

Beispiel #2 Prozeduraler Stil

<?php
/* Open a connection */
$link mysqli_connect("localhost""my_user""my_password""world");

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

$query "SELECT Name, CountryCode FROM City ORDER BY Name LIMIT 20";
if (
$stmt mysqli_prepare($link$query)) {

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

    
/* store result */
    
mysqli_stmt_store_result($stmt);

    
printf("Number of rows: %d.\n"mysqli_stmt_num_rows($stmt));

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

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

Die obigen Bespiele erzeugen folgende Ausgabe:

Number of rows: 20.

Siehe auch

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User Contributed Notes 1 note

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23
Typer85 at gmail dot com
7 years ago
Please be advised, for people who sometimes miss to read this important Manual entry for this function:

If you do not use mysqli_stmt_store_result( ), and immediatley call this function after executing a prepared statement, this function will usually return 0 as it has no way to know how many rows are in the result set as the result set is not saved in memory yet.

mysqli_stmt_store_result( ) saves the result set in memory thus you can immedietly use this function after you both execute the statement AND save the result set.

If you do not save the result set but still want to use this function you have to actually loop through the result set one row at a time using mysqli_stmt_fetch( ) before using this function to determine the number of rows.

A thought though, if you want to determine the number of rows without storing the result set and after looping through it, why not just simply keep an internal counter in your loop every time a row is fetched and save the function call.

In short, this function is only really useful if you save the result set and want to determine the number of rows before looping through it, otherwise you can pretty much recreate its use like I suggested.
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