PHP MySQLi mysqli_num_rows()

mysqli_num_rows()

The mysqli_num_rows() function returns the number of rows in a result set. This function only works with queries that return a data set, such as SELECT.

EXAMPLE

<?php
$server = "localhost";
$username = "root";
$password = "";
$database = "mysqli_database";

$connection = mysqli_connect($server, $username, $password, $database);

if (mysqli_connect_errno()) {
    echo "Connection failed: " . mysqli_connect_error();
    exit();
}

$sql = "SELECT * FROM mysqli_table";

if ($result = mysqli_query($connection, $sql)) {
    // Get the number of rows in the result
    // NOTE: The mysqli_num_rows() function requires the $result variable 
    // of a successfully executed query. It counts the rows that matched 
    // the conditions. In our case, it will output the number 4.
    $count = mysqli_num_rows($result);
    
    printf("The table has %d rows.", $count);
    
    mysqli_free_result($result);
}

mysqli_close($connection);
?>

RESULT

The result will be displayed here...

Practical use: It is very useful when you want to check if a query found any records before trying to output them. If the function returns 0, you know that the table is empty or that no records match your criteria.

It returns an integer representing the number of rows.

It is used exclusively on the results of SELECT queries.

To determine the number of affected rows in an UPDATE, use mysqli_affected_rows().