PostgreSQL extensions

This page is about PostgreSQL extensions and explains how to use them with Prisma ORM.

What are PostgreSQL extensions?

PostgreSQL allows you to extend your database functionality by installing and activating packages known as extensions. For example, the citext extension adds a case-insensitive string data type. Some extensions, such as citext, are supplied directly by PostgreSQL, while other extensions are developed externally. For more information on extensions, see the PostgreSQL documentation.

To use an extension, it must first be installed on the local file system of your database server. You then need to activate the extension, which runs a script file that adds the new functionality.

Using a PostgreSQL extension with Prisma ORM

Let's walk through an example of installing the citext extension.

1. Create an empty migration

Run the following command to create an empty migration that you can customize:

npx prisma migrate dev --create-only

2. Add a SQL statement to install the extension

In the new migration file that was created in the migrations directory, add the following statement:

CREATE EXTENSION IF NOT EXISTS citext;

3. Deploy the migration

Run the following command to deploy the migration and apply to your database:

npx prisma migrate deploy

4. Use the extension

You can now use the extension in your queries with Prisma Client. If the extension has special data types that currently can't be natively represented in the Prisma schema, you can still define fields of that type on your models using the Unsupported fallback type.

PostGIS extension for spatial data

PostGIS enables spatial and geographic objects for PostgreSQL, allowing you to store and query location data, routes, boundaries, and other geographic features. Prisma ORM provides native support for PostGIS geometry types.

Prerequisites

1. Install PostGIS on your PostgreSQL server
2. Enable the extension in your database:

CREATE EXTENSION IF NOT EXISTS postgis;

Using the Geometry type

Once PostGIS is enabled, you can use the native Geometry type in your Prisma schema:

model Location {
  id       Int      @id @default(autoincrement())
  name     String
  position Geometry(Point, 4326)?
}

model Route {
  id   Int      @id @default(autoincrement())
  name String
  path Geometry(LineString, 4326)?
}

model Zone {
  id       Int      @id @default(autoincrement())
  name     String
  boundary Geometry(Polygon, 4326)?
}

The Geometry type supports various shapes:

• Point - Single location (e.g., restaurant, store)
• LineString - Path or route
• Polygon - Area or boundary
• MultiPoint, MultiLineString, MultiPolygon - Collections of geometries

Native spatial operations

Prisma Client provides native filters and ordering for spatial queries:

// Find locations within 1km radius
const nearby = await prisma.location.findMany({
  where: {
    position: {
      near: {
        point: [13.4, 52.5],
        maxDistance: 1000,
      },
    },
  },
});

// Find points within a polygon boundary
const withinArea = await prisma.location.findMany({
  where: {
    position: {
      within: {
        polygon: [
          [0, 0],
          [0, 10],
          [10, 10],
          [10, 0],
          [0, 0],
        ],
      },
    },
  },
});

// Sort by distance from a reference point
const sorted = await prisma.location.findMany({
  orderBy: {
    position: {
      distanceFrom: {
        point: [13.4, 52.5],
        direction: "asc",
      },
    },
  },
  take: 10,
});

For detailed usage, examples, and real-world use cases, see Working with geometry fields.