<?php

$dbfilename = 'demo.db';

if (is_file($dbfilename)) {
    unlink($dbfilename);
}

$sql = 'CREATE TABLE demo (id int, name string)';
$result = demoQuery($dbfilename, $sql);
var_dump($result);

$sql = 'SELECT * FROM demo WHERE id=0';
$rows = demoQuery($dbfilename, $sql);
var_dump($rows);

$sql = 'INSERT INTO demo VALUES (0, "A")';
$result = demoQuery($dbfilename, $sql);
var_dump($result);

$sql = 'SELECT * FROM demo WHERE id=0';
$rows = demoQuery($dbfilename, $sql);
var_dump($rows);

function demoQuery(string $dbfilename, string $sql) : array {
    $fetchable = (0===stripos(trim($sql), 'select'));

    $db = new SQLite3($dbfilename);
    if ($db === false) {
        throw new Exception("demoQuery: open error " . $dbfilename);
    }

    //$result = $db->query($sql);
    $stmt = $db->prepare($sql);
    if ($stmt === false) {
        throw new Exception("demoQuery: prepare error " . $sql);
    }

    // TODO //$stmt->bindvalue();
    $result = $stmt->execute();
    if ($result === false) {
        throw new Exception("demoQuery: execute query error " . $sql);
    }

    $rows = [];
    if (true) { // Expected to work before reading internals of PHP+SQLite3
    //if ($fetchable) { // May work
    //if ($result->columnName(0) !== false) { // Works
    //if ($result->columnType(0)!=SQLITE3_NULL) { // Didnt work
    //if ($result->fetchArray()) { // Dangerous
    //if ($result->finalize()) { // Cant do that
    //if ($result->numColumns()!==0) { // Works
    //if ($result->reset()) { // Didnt work
    //if ($result->columnName(0) !== false || $result->numColumns()!==0) { // My best
        while ($row = $result->fetchArray()) {
            $rows[] = $row;
        }
    }
    $db->close();
    return $rows;
}