Postgres Geolocation example

This example shows how to implement Geolocation in PostgreSQL using Express, Postgis and Prisma Client.

Getting started

1. Download example and navigate into the project directory

Download this example:

npx try-prisma@latest --template orm/postgis-express --install npm --name postgis-express

Then, navigate into the project directory:

cd postgis-express

Alternative: Clone the entire repo

Clone this repository:

git clone git@github.com:prisma/prisma-examples.git --depth=1

Install npm dependencies:

cd prisma-examples/orm/postgis-express
npm install

2. Setup PostgreSQL

The recommended way of trying this out would be using a Docker image of PostgreSQL with Postgis extensions that can be pulled from here.
A docker-compose.yml is included for a quick start so that you do not need any prior setup. Just run docker-compose up -d and Postgres will be up and running on PORT 5432 with username postgres and database geoexample.
Connect to Postgres by any database viewer of your choice.
Rename the .env.example to .env and replace the DBNAME placeholder with the database name geoexample created in the above step.

Run the following command to create the tables and the function required for this example.

npx prisma migrate deploy

Lastly run the following command to generate Prisma Client.

npx prisma generate

Limitation: Currently Prisma doesn't support custom data types, so querying for the geography type in the normal Prisma models is not possible. Operations can only be performed on the types via prisma.$queryRaw or prisma.$executeRaw. You can learn more about unsupported types here.

3. Start the REST API server

Execute this command to start the server:

npm run dev

The server is now running on http://localhost:3000. You can send the API requests implemented in index.ts

Using the API

You can access the API using the following endpoints:

`POST`

/user: Create a new User
- Body:
  - name: String (required): The name of the user
  - location: Object (required): The location object specified via lat and lng
    - lat: Number (required): The latitude of the user's location
    - lng: Number (required): The longitude of the user's location
/location: Create a new Location
- Body:
  - name: String (required): The name of the location
  - location: Object (required): The location object specified via lat and lng
    - lat: Number (required): The latitude of the given location
    - lng: Number (required): The longitude of the given location

`GET`

/:userId/nearby-places?d={d}: Fetch locations within the specified radius of the user's location
- Params:
  - userId: String (required): The id of the user
- Query Params:
  - d: String (optional): The distance in kms. Default is 5

Seeding data

Add data of your choice to the "User" and "Location" tables with the above endpoints and then run the GET endpoint passing the required parameters.

Next steps

Check out the Prisma docs
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Report issues or ask questions on GitHub.