Planetscale is a MySQL-compatible serverless database that is designed with adeveloper workflow where developers can create, branch, and deploy databasesfrom the command line.

View source here.

We'll use the Planetscale serverless driver,@planetscale/database, to workwith Deno. First we want to createmain.ts and import the connect method fromthis package:

import{ connect}from"npm:@planetscale/database@^1.4";

Configuring our connectionJump to heading#

The connection requires three credentials: host, username, and password. Theseare database-specific, so we first need to create a database in Planetscale. Youcan do that by following the initial instructionshere.Don't worry about adding the schema—we can do that through@planetscale/database.

Once you have created the database, head to Overview, click "Connect", andchoose "Connect with@planetscale/database" to get the host and username. Thenclick through to Passwords to create a new password for your database. Once youhave all three you can plug them in directly, or better, store them asenvironment variables:

exportHOST=<host>exportUSERNAME=<username>exportPASSWORD=<password>

Then call them usingDeno.env:

const config={  host: Deno.env.get("HOST"),  username: Deno.env.get("USERNAME"),  password: Deno.env.get("PASSWORD"),};const conn=connect(config);

This will also work on Deno Deploy if you set the environment variables in thedashboard. Run with:

deno run --allow-net --allow-env main.ts

Theconn object is now an open connection to our Planetscale database.

Creating and populating our database tableJump to heading#

Now that you have the connection running, you can conn.execute() with SQLcommands to create tables and insert the initial data:

await conn.execute("CREATE TABLE dinosaurs (id int NOT NULL AUTO_INCREMENT PRIMARY KEY, name varchar(255) NOT NULL, description varchar(255) NOT NULL);",);await conn.execute("INSERT INTO `dinosaurs` (id, name, description) VALUES (1, 'Aardonyx', 'An early stage in the evolution of sauropods.'), (2, 'Abelisaurus', 'Abels lizard has been reconstructed from a single skull.'), (3, 'Deno', 'The fastest dinosaur that ever lived.')",);

Querying PlanetscaleJump to heading#

We can use sameconn.execute() to also write our queries. Let's get a list ofall our dinosaurs:

const results=await conn.execute("SELECT * FROM `dinosaurs`");console.log(results.rows);

The result:

[{    id:1,    name:"Aardonyx",    description:"An early stage in the evolution of sauropods.",},{    id:2,    name:"Abelisaurus",    description:"Abels lizard has been reconstructed from a single skull.",},{ id:3, name:"Deno", description:"The fastest dinosaur that ever lived."},];

We can also get just a single row from the database by specifying a dinosaurname:

const result=await conn.execute("SELECT * FROM `dinosaurs` WHERE `name` = 'Deno'",);console.log(result.rows);

Which gives us a single row result:

[{ id:3, name:"Deno", description:"The fastest dinosaur that ever lived."}];

You can find out more about working with Planetscale in theirdocs.