text: DROP TABLE account;
  CREATE TABLE IF NOT EXISTS account (
    id          INT NOT NULL PRIMARY KEY,
    name        NVARCHAR2(100) NOT NULL,
    password    NVARCHAR2(20),
    role        INT
  );
  CREATE TABLE IF NOT EXISTS customer (
    id          INT NOT NULL PRIMARY KEY,
    postal_code NVARCHAR2(10),
    address     NVARCHAR2(100),
    phone       NVARCHAR2(20)
  );
  