SQLite3计数行

Question

I am trying to count the number of rows returned from a query

This is currently the code I have

function products()
{
$loggedin = loggedin();
$db = db();

$stmt = $db->prepare('SELECT game_id, name, developer, price FROM game   WHERE quantity > 0 ORDER BY game_id DESC');
$result = $stmt->execute();
$row1 = $result->fetchArray();
$rows = count ($row1); 

if ($rows == 0)
    {
    echo "Sold out";
    }
else
    {
    while ($row = $result->fetchArray()) {
    echo '<p>'.$row['name'].'</p>';

    }
    }
}

At present it will only return the first item in the table, even though all rows match

if I change my code to

function products()
{
$loggedin = loggedin();
#$page = 'index.php';
$db = db();
$stmt = $db->prepare('SELECT game_id, name, developer, price FROM game   WHERE quantity > 11 ORDER BY game_id DESC');
$result = $stmt->execute();
while ($row = $result->fetchArray()) {
    echo '<p>'.$row['name'].'</p>';

}

Then I get all the result from the table correctly

if I change the query to a value outside the quantity like

quantity > 20

then I get the error

Warning: count(): Parameter must be an array or an object that implements Countable

what I would like it to do is if row1 is == 0 the show sold out other wise display all the rows

so if a row does not match the query it will not be included in the results I can not use PDO, and I have not been able to find out to use count on https://www.php.net/manual/en/book.sqlite3.php

Answer 1

That should do it.

function products() {
    $loggedin = loggedin();
    $db = db();
    $games = $db->query('SELECT game_id, name, developer, price FROM game WHERE quantity > 0 ORDER BY game_id DESC');

    if (empty($games->fetchArray())) {
        echo "Sold out";
        return;
    }

    // Reset the result back to the first game
    $games->reset();

    while ($game = $games->fetchArray(SQLITE3_ASSOC)) {
        echo '<p>'.$game['name'].'</p>';  
    }
}

Answer 2

I'd do something like:

function products() {
    $db = db();
    $stmt = $db->prepare('SELECT game_id, name, developer, price FROM game WHERE quantity > 0 ORDER BY game_id DESC');
    $result = $stmt->execute();
    $count = 0;

    while ($row = $result->fetchArray()) {
        echo '<p>'.$row['name'].'</p>';
        $count++;  
    }

    if ($count == 0) {
        echo "<p>Sold out</p>";
    }
}

The only way to find out how many rows were returned by a query is to fetch all of them (and you don't actually care how many rows were returned, just that at least one was). So just increment a counter once per row returned, and after stepping through all rows, if that counter is still 0, it means no rows were returned, and you can display the relevant message.