Database design

import { integer, sqliteTable, text } from "drizzle-orm/sqlite-core";
import {sql} from 'drizzle-orm'

const timeStamps = {createdAt: integer( { mode: "timestamp_ms" })
    .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
    .notNull(),
  updatedAt: integer({ mode: "timestamp_ms" })
    .default(sql`(cast(unixepoch('subsecond') * 1000 as integer))`)
    .$onUpdate(() => /* @__PURE__ */ new Date())
    .notNull()}
 
export const $user = sqliteTable("user", {
  id: integer({mode: 'number'}).primaryKey({autoIncrement: true}),
  firstName: text().notNull(),
  lastName: text().notNull(),
  email: text().notNull().unique(),
  image: text(),
  password: text().notNull(),
  ...timestamps
});

export const $class = sqliteTable('classes', {
    id: integer().primaryKey({ autoIncrement: true}),
    name: text().notNull(),
    teacherId: integer().references(() => $teacher.id),
    ...timeStamps
}) 

export const $teacher = sqliteTable('teachers', {
    id: integer().primaryKey({autoIncrement: true}),
    userId: integer().notNull().references(() => $user.id),
    ...timeStamps
})


export const $student = sqliteTable('students', {
    id: integer().primaryKey({autoIncrement: true}),
    userId: integer().notNull().references(() => $user.id),
    classId: integer().references(() => $class.id),
    ...timeStamps
})