02. SoftUni SQL

<?php
//$commands = $_GET['commands'];
$commands = ["UPDAtE users SET (age = 30) WHERE (user_id = 1)", "INSERT INTO users (login, age, gender) VALUES (yana, 20, female)", "UPDATE users SET (age = 30) WHERE (user_id = 1)", "INSERT INTO users (login, age) VALUES (yana, 20, female)", "INSERT INTO users (login, age, gender) VALUES (yana, 20, female)", "INSERT INTO users (user_id, login, gender) VALUES (12, yana, female)", "INSERT INTO users (login, age, gender) VALUES (yana, 20, female)", "INSrRT INTO users (login, age, gender) VALUES (yana, 20, female)", "UPDATE users SET (age = 30) WHERE (user_id = 1)", "UPDATE users SET (age = 30) WHERE (age = undefined)", "DELETE FROM users WHERE (age = 30)"];

$insertRegex = '/INSERT INTO (\w+) \((.+)\) VALUES \((.+)\)/';
$updateRegex = '/UPDATE (\w+) SET \((\w+) = (\w+)\) WHERE \((\w+) = (\w+)\)/';
$deleteRegex = '/DELETE FROM (\w+) WHERE \((\w+) = (\w+)\)/';

$errors = 0;
$lastID = -1;
foreach ($commands as $command) {
    if (preg_match($insertRegex, $command, $insertMatch)) {
        $fields = explode(', ', $insertMatch[2]);
        $values = explode(', ', $insertMatch[3]);
        if (array_search('login', $fields) === false) {
            $errors++;
            continue;
        } else if (count($fields) != count($values)) {
            $errors++;
            continue;
        }
        if (array_search('user_id', $fields) !== false) {
            $id = array_search('user_id', $fields);
            $lastID = $values[$id];
        } else {
            $lastID += 1;
        }

        $login = $values[array_search('login', $fields)];

        if (array_search('gender', $fields) !== false) {
            $gender = $values[array_search('gender', $fields)];
        } else {
            $gender = 'undefined';
        }
        if (array_search('age', $fields) !== false) {
            $age = $values[array_search('age', $fields)];
        } else {
            $age = 'undefined';
        }
        $table[$lastID]['login'] = $login;
        $table[$lastID]['gender'] = $gender;
        $table[$lastID]['age'] = $age;

    } else if (preg_match($updateRegex, $command, $updateMatch)) {
//        $updateField = $updateMatch[2];
//        $existingField = false;
//        if ($updateMatch[4] == 'user_id') {
//            if (isset($table[$updateMatch[5]])) {
//                $existingField = true;
//            }
//        } else {
//            foreach ($table as $key => $value) {
//                foreach ($table[$key] as $field => $fieldValue) {
//                    if ($field == $updateMatch[4]) {
//                        $existingField = true;
//                    }
//                }
//            }
//            if ($existingField) {
//                if ($updateMatch[4] == 'user_id') {
//                    $table[$updateMatch[5]][$updateMatch[2]] = $updateMatch[3];
//                } else {
//
//                }
//            } else {
//                $errors++;
//                continue;
//            }
//
//        }

    } else if (preg_match($deleteRegex, $command, $deleteMatch)) {

    } else {
        $errors++;
    }
}