text: 
  create table t_department(
    id integer primary key autoincrement,
    name varchar(128) not null,
    location varchar(128) not null
  );
  
  create table t_employee(
    id integer primary key autoincrement,
    name varchar(128) not null,
    job varchar(128) not null,
    manager_id int null,
    hire_date varchar(10) not null,
    salary bigint not null,
    department_id int not null
  );
  
  insert into t_department(name, location) values ('tech', 'Guangzhou');
  insert into t_department(name, location) values ('finance', 'Beijing');
  
  insert into t_employee(name, job, manager_id, hire_date, salary, department_id)
  values ('vince', 'engineer', null, '2018-01-01', 100, 1);
  insert into t_employee(name, job, manager_id, hire_date, salary, department_id)
  values ('marry', 'trainee', 1, '2019-01-01', 50, 1);
  
  insert into t_employee(name, job, manager_id, hire_date, salary, department_id)
  values ('tom', 'director', null, '2018-01-01', 200, 2);
  insert into t_employee(name, job, manager_id, hire_date, salary, department_id)
  values ('penny', 'assistant', 3, '2019-01-01', 100, 2);
  