text: USE [EXPENSE]
  GO
  CREATE TABLE [dbo].[accounts] (
  	username username_ty,
  	firstname firstname_ty,
  	lastname lastname_ty,
  	email email_ty,
  	password password_ty,
  	PRIMARY KEY(username),
  	CONSTRAINT chk_username CHECK(dbo.isAlphanumeric(username) = 1)
  );
  GO