pdo.php

<?php

/*
    Description: PDO PHP
    Author: Viktor Kasko
    github.com/Examplio
*/

class Db {
    private static ?Db $instance = null;
    private PDO $db;

    private function __construct(string $host, string $dbName, string $user, string $password) {
        try {
            $dsn = "mysql:host=$host;dbname=$dbName;charset=utf8mb4;port=3306";
            $this->db = new PDO($dsn, $user, $password, [
                PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_EMULATE_PREPARES   => false,
                PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
            ]);
            $this->db->query("SET lc_time_names = 'ru_RU'");
        } catch (PDOException $e) {
            die("Catched error with connection to db: " . $e->getMessage());
        }
    }

    public static function getInstance(string $host = "", string $dbName = "", string $user = "", string $password = ""): Db {
        if (self::$instance === null) {
            self::$instance = new self($host, $dbName, $user, $password);
        }
        return self::$instance;
    }

    public function query(string $query, array $params = []): array|bool {
        try {
            $sth = $this->db->prepare($query);
            $sth->execute($params);
            return $sth->fetchAll();
        } catch (PDOException $e) {
            return false;
        }
    }

    public function insert(string $table, array $data): bool {
        $columns = implode(", ", array_keys($data));
        $placeholders = implode(", ", array_fill(0, count($data), "?"));
        $query = "INSERT INTO $table ($columns) VALUES ($placeholders)";

        return $this->executeQuery($query, array_values($data));
    }

    public function select(string $table, array|string $columns = "*", array $condition = []): array|bool {
        $columns = is_array($columns) ? implode(", ", $columns) : $columns;
        $whereClause = $this->buildWhereClause($condition);
        $query = "SELECT $columns FROM $table" . $whereClause['sql'];

        return $this->query($query, $whereClause['params']);
    }

    public function update(string $table, array $data, array $condition): bool {
        $setClause = implode(", ", array_map(fn($key) => "`$key` = ?", array_keys($data)));
        $whereClause = $this->buildWhereClause($condition);

        $query = "UPDATE $table SET $setClause" . $whereClause['sql'];
        return $this->executeQuery($query, array_merge(array_values($data), $whereClause['params']));
    }

    public function delete(string $table, array $condition): bool {
        $whereClause = $this->buildWhereClause($condition);
        $query = "DELETE FROM $table" . $whereClause['sql'];

        return $this->executeQuery($query, $whereClause['params']);
    }

    public function getLastId(): int {
        return (int) $this->db->lastInsertId();
    }

    private function executeQuery(string $query, array $params): bool {
        try {
            $sth = $this->db->prepare($query);
            return $sth->execute($params);
        } catch (PDOException $e) {
            return false;
        }
    }

    private function buildWhereClause(array $condition): array {
        if (empty($condition)) return ['sql' => '', 'params' => []];

        $whereParts = array_map(fn($key) => "`$key` = ?", array_keys($condition));
        return [
            'sql' => " WHERE " . implode(" AND ", $whereParts),
            'params' => array_values($condition)
        ];
    }

    public function __destruct() {
        $this->db = null;
    }
}

?>