# Use Gel with Bun

Gel (formerly EdgeDB) is a graph-relational database built on Postgres. It provides a declarative schema language, migrations system, and object-oriented query language. It also supports raw SQL queries. It solves object-relational mapping at the database layer, so your application code doesn't need an ORM library.

---

First, [install Gel](https://docs.geldata.com/learn/installation) if you haven't already.

<CodeGroup>

```sh Linux/macOS terminal icon="terminal"
curl https://www.geldata.com/sh --proto "=https" -sSf1 | sh
```

```sh Windows terminal icon="windows"
irm https://www.geldata.com/ps1 | iex
```

```sh Homebrew terminal icon="terminal"
brew install geldata/tap/gel-cli
```

</CodeGroup>

---

Use `bun init` to create a fresh project.

```sh terminal icon="terminal"
mkdir my-gel-app
cd my-gel-app
bun init -y
```

---

Initialize a Gel instance for the project with the Gel CLI. The `gel project init` command creates a `gel.toml` file in the project root.

```sh terminal icon="terminal"
gel project init
```

```txt
No `gel.toml` (or `edgedb.toml`) found in `/Users/colinmcd94/Documents/bun/fun/examples/my-gel-app` or above
Initializing new project...
Checking Gel versions...
┌─────────────────────┬──────────────────────────────────────────────────────────────────┐
│ Project directory   │ /Users/colinmcd94/Documents/bun/fun/examples/my-gel-app          │
│ Project config      │ /Users/colinmcd94/Documents/bun/fun/examples/my-gel-app/gel.toml │
│ Schema dir (empty)  │ /Users/colinmcd94/Documents/bun/fun/examples/my-gel-app/dbschema │
│ Installation method │ portable package                                                 │
│ Version             │ x.y+6d5921b                                                      │
│ Instance name       │ my_gel_app                                                       │
│ Branch              │ main                                                             │
└─────────────────────┴──────────────────────────────────────────────────────────────────┘
Version x.y+6d5921b is already downloaded
Initializing Gel instance 'my_gel_app'...
Applying migrations...
Everything is up to date. Revision initial
Writing gel.local.toml for configuration
Project initialized.
To connect to my_gel_app, run `gel`
```

---

To check that the database is running, open a REPL and run a query.

```sh terminal icon="terminal"
gel
my_gel_app:main> select 1 + 1;
```

```txt
{2}
```

Then run `\quit` to exit the REPL.

```sh terminal icon="terminal"
my_gel_app:main> \quit
```

---

Next, define a schema. The `gel project init` command already created a `dbschema/default.gel` file to hold it.

```txt File Tree icon="folder-tree"
dbschema
├── default.gel
├── extensions.gel
├── futures.gel
└── migrations
```

---

Open that file and paste the following contents.

```ts default.gel icon="file-code"
module default {
  type Movie {
    required title: str;
    releaseYear: int64;
  }
};
```

---

Then generate and apply an initial migration.

```sh terminal icon="terminal"
gel migration create
```

```txt
Created dbschema/migrations/00001-m1uwekr.edgeql, id: m1uwekrn4ni4qs7ul7hfar4xemm5kkxlpswolcoyqj3xdhweomwjrq
```

```sh terminal icon="terminal"
gel migrate
```

```txt
Applying m1uwekrn4ni4qs7ul7hfar4xemm5kkxlpswolcoyqj3xdhweomwjrq (00001-m1uwekr.edgeql)
... parsed
... applied
```

---

With the schema applied, query the database with Gel's JavaScript client library. Install the client library and Gel's codegen CLI, then create a `seed.ts` file.

```sh terminal icon="terminal"
bun add gel
bun add -D @gel/generate
touch seed.ts
```

---

Paste the following code into `seed.ts`.

The client auto-connects to the database. The script inserts a few movies with the `.execute()` method, using EdgeQL's `for` expression to turn the bulk insert into a single query.

```ts seed.ts icon="/icons/typescript.svg"
import { createClient } from "gel";

const client = createClient();

const INSERT_MOVIE = `
  with movies := <array<tuple<title: str, year: int64>>>$movies
  for movie in array_unpack(movies) union (
    insert Movie {
      title := movie.title,
      releaseYear := movie.year,
    }
  )
`;

const movies = [
  { title: "The Matrix", year: 1999 },
  { title: "The Matrix Reloaded", year: 2003 },
  { title: "The Matrix Revolutions", year: 2003 },
];

await client.execute(INSERT_MOVIE, { movies });

console.log(`Seeding complete.`);
process.exit();
```

---

Then run this file with Bun.

```sh terminal icon="terminal"
bun run seed.ts
```

```txt
Seeding complete.
```

---

Gel implements several code generation tools for TypeScript. To write typesafe queries against the seeded database, generate the EdgeQL query builder with `@gel/generate`.

```sh terminal icon="terminal"
bunx @gel/generate edgeql-js
```

```txt
Generating query builder...
Detected tsconfig.json, generating TypeScript files.
   To override this, use the --target flag.
   Run `npx @gel/generate --help` for full options.
Introspecting database schema...
Writing files to ./dbschema/edgeql-js
Generation complete! 🤘
Checking the generated query builder into version control
is not recommended. Would you like to update .gitignore to ignore
the query builder directory? The following line will be added:

   dbschema/edgeql-js

[y/n] (leave blank for "y")
> y
```

---

In `index.ts`, import the generated query builder from `./dbschema/edgeql-js` and write a select query.

```ts index.ts icon="/icons/typescript.svg"
import { createClient } from "gel";
import e from "./dbschema/edgeql-js";

const client = createClient();

const query = e.select(e.Movie, () => ({
  title: true,
  releaseYear: true,
}));

const results = await query.run(client);
console.log(results);

results; // { title: string, releaseYear: number | null }[]
```

---

Run the file with Bun to see the movies you inserted.

```sh terminal icon="terminal"
bun run index.ts
```

```txt
[
  {
    title: "The Matrix",
    releaseYear: 1999,
  }, {
    title: "The Matrix Reloaded",
    releaseYear: 2003,
  }, {
    title: "The Matrix Revolutions",
    releaseYear: 2003,
  }
]
```

---

See the [Gel docs](https://docs.geldata.com/).