13## A Few Honkin' Notes
14
15### database migrations need love and care 🫂
16
17Not totally sure how to generate and apply drizzle migrations yet!
5 * For this reason, we need to manually create the users table.
6 */
7export const migrateDatabase = async () => {
8 await sqlite.execute(`
9CREATE TABLE IF NOT EXISTS \`users\` (
6import usersApi from "./app/users.ts";
7import { db } from "./db/client.ts";
8import { migrateDatabase } from "./db/migrate.ts";
9
10// Migrate database on startup to make sure the proper table exists to store users
11// NOTE - Please comment on the template project if you have ideas on how to do migrations more cleanly on Valtown
12await migrateDatabase();
13
14const app = new Hono<AppType>();
15
16/**
17 * Middleware for setting up the database and storing it on the Hono app's context
18 */
19app.use(async (c, next) => {
1// Import drizzle deps with npm: specifier because exports don't get picked up properly by typescript when using esm.sh
2import { drizzle, type LibSQLDatabase } from "npm:drizzle-orm@0.39.3/libsql";
3import { and, eq, desc, relations, sql } from "npm:drizzle-orm@0.39.3";
4import { integer, sqliteTable, text } from "npm:drizzle-orm@0.39.3/sqlite-core";
5
6export { drizzle };
7export type { LibSQLDatabase };
8export { and, eq, desc, relations, sql };
9export { integer, sqliteTable, text };
5
6/**
7 * The typed database client, allowing us to construct sql queries and
8 * use Drizzle's ORM features against the ValTown sqlite database
9 */
10export const db: DBType = drizzle(sqlite as any, {
9- The **client-side entrypoint** is `/frontend/index.html`, which in turn imports `/frontend/index.tsx`, which in turn imports the React app from `/frontend/components/App.tsx`.
10
11[React Hono Example](https://www.val.town/x/stevekrouse/reactHonoExample) is a fuller featured example project, with a SQLite database table, queries, client-side CSS and a favicon, and some shared code that runs on both client and server.
1import { sqlite } from "https://esm.town/v/std/sqlite";
2
3// Initialize the database schema if not exists
4async function initializeDatabase() {
5 try {
6 // Create the table with explicit column types
32 }
33 } catch (error) {
34 console.error("Database initialization error:", error);
35 }
36}
100// Main request handler
101export default async function(req: Request): Promise<Response> {
102 // Initialize database on every request (quick operation if already created)
103 await initializeDatabase();
104
105 const url = new URL(req.url);
140 }
141
142 // Insert the new speed into the database
143 await sqlite.execute({
144 sql: `INSERT INTO train_speeds (speed) VALUES (:speed)`,
4
5* `index.ts` - this is the **entrypoint** for this whole project
6* `database/` - this contains the code for interfacing with the app's SQLite database table
7
8## Hono
26## CRUD API Routes
27
28This app has two CRUD API routes: for reading and inserting into the messages table. They both speak JSON, which is standard. They import their functions from `/backend/database/queries.ts`. These routes are called from the React app to refresh and update data.
29
30## Errors
1# Database
2
3This app uses [Val Town SQLite](https://docs.val.town/std/sqlite/) to manage data. Every Val Town account comes with a free SQLite database, hosted on [Turso](https://turso.tech/). This folder is broken up into two files:
4
5* `migrations.ts` - code to set up the database tables the app needs
6* `queries.ts` - functions to run queries against those tables, which are imported and used in the main Hono server in `/backend/index.ts`
7
8## Migrations
9
10In `backend/database/migrations.ts`, this app creates a new SQLite table `reactHonoStarter_messages` to store messages.
11
12This "migration" runs once on every app startup because it's imported in `index.ts`. You can comment this line out for a slight (30ms) performance improvement on cold starts. It's left in so that users who fork this project will have the migration run correctly.
13
14SQLite has much more limited support for altering existing tables as compared to other databases. Often it's easier to create new tables with the schema you want, and then copy the data over. Happily LLMs are quite good at those sort of database operations, but please reach out in the [Val Town Discord](https://discord.com/invite/dHv45uN5RY) if you need help.
15
16## Queries
17
18The queries file is where running the migrations happen in this app. It'd also be reasonable for that to happen in index.ts, or as is said above, for that line to be commented out, and only run when actual changes are made to your database schema.
19
20The queries file exports functions to get and write data. It relies on shared types and data imported from the `/shared` directory.
3import { createTables, tableName } from "./migrations.ts";
4
5// This will create the database table if it doesn't exist.
6// This will run every time the app starts up. You can
7// comment out this line for a modest (30ms) perforamnce improvement
8// on cold starts. It's left in to ensure the database tables are
9// automatically set up correctly for users who fork this app.
10await createTables();