text: DROP TABLE IF EXISTS dept;
  DROP TABLE IF EXISTS employeeRole;
  DROP TABLE IF EXISTS employeeInfo;
  
  CREATE TABLE dept (
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(50) NOT NULL
  );
  
  CREATE TABLE employeeRole (
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(30) NOT NULL,
    salary DECIMAL NOT NULL,
    dept_id INTEGER,
    CONSTRAINT fk_dept FOREIGN KEY (dept_id) REFERENCES dept(id) ON DELETE SET NULL
  );
  
  CREATE TABLE employeeInfo (
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    first_name VARCHAR(30) NOT NULL,
    last_name VARCHAR(30) NOT NULL,
    manager_id INTEGER,
    role_id INTEGER,
    dept_id INTEGER,
    CONSTRAINT fk_role FOREIGN KEY (role_id) REFERENCES employeeRole(id) ON DELETE SET NULL,
    CONSTRAINT fk_deptid FOREIGN KEY (dept_id) REFERENCES dept(id) ON DELETE SET NULL
  );