Simple class for connection in MySQL database using PDO library

database.php

<?php

namespace database;

use PDO;

class connection {
  private $database;

  public function __construct() {
    $host = 'localhost';
    $database = 'telegram';
    $username = 'root';
    $password = 'root';
    $dsn = 'mysql:host='.$host.';dbname=' . $database;
    $user = $username;
    $pass = $password;
    try {
      $this->database = new PDO($dsn, $user, $pass);
    } catch (\Throwable $th) {
      throw $th;
    }
  }

    /**
     * @return PDO
     */
  public function getDatabase(): PDO
  {
      return $this->database;
  }

    /**
     * @param string $sql
     * @param array $parameters
     * @return array
     */
  public function runQuery(string $sql, array $parameters = []): array
  {
    $statement = $this->database->prepare($sql);
    $statement->execute($parameters);
    return $statement->fetchAll(PDO::FETCH_ASSOC);
  }

    /**
     * @param string $tableName
     * @param array $fields
     * @param array $where
     * @return array
     */
  public function select(string $tableName, array $fields = [], array $where = []): array
  {
      if (count($fields) === 0) {
          $sql = "select * from {$tableName}";
      } else {
          $fields = implode(', ', $fields);
          $sql = "select {$fields} from {$tableName}";
      }
      if (count($where) > 0) {
          if (count($where) === 2) {
              $sql .= " where " . $where[0] . " = " . $where[1];
          } else {
              $sql .= " where " . $where[0] . $where[1] . '"'. $where[2] .'"';
          }
      }
      return $this->runQuery($sql, []);
  }

    /**
     * @param string $table
     * @param array $fieldsAndValues
     * @return array
     */
    public function create(string $table, array $fieldsAndValues = []): array
    {
        $keys = "";
        $values = "";
        foreach ($fieldsAndValues as $key => $value) {
            $keys .= $key . ", ";
        }
        foreach ($fieldsAndValues as $key => $value) {
            $values .= '"' . $value . '", ';
        }
        $keys = substr($keys, 0, -2);
        $values = substr($values, 0, -2);
        $sql = "insert into {$table} ($keys) values ($values)";
        return $this->runQuery($sql);
    }
}