MongoDB

Add a MongoDB database as an external catalog in Altertable to query its collections with SQL alongside your other data sources. Each collection in the connected database appears as a table.

Prerequisites

Allow Altertable egress IPs

If inbound traffic is restricted—including MongoDB Atlas IP access lists—allow Altertable's egress IP addresses so Workers can connect.

For Atlas:

1. Open the Atlas project and go to Network Access
2. Click Add IP Address
3. Add each egress IP address (Atlas accepts the address or address/32)
4. Confirm the entries are active before you test the catalog in Altertable

You can also connect a self-hosted MongoDB server through an SSH tunnel.

Create a database user

Use a MongoDB database user, not your Atlas organization login. In Atlas, create the user under Database Access with read access to the database you will query.

Connecting to Altertable

To add a new MongoDB external catalog:

1. Navigate to the Catalogs section in the dashboard
2. Click New catalog
3. Select MongoDB as the engine
4. Fill in the connection details:
   • Connection string (optional): Paste a mongodb:// or mongodb+srv:// URL to fill Host, username, SRV, and related options. Enter the password separately. Atlas connection strings often omit the database name, so you still need to set Database.
   • Host: The hostname. For Atlas, use the hostname from the connection string, such as cluster0.xxxxx.mongodb.net—without mongodb+srv:// or credentials.
   • Port: Default 27017. Leave it empty when SRV connection is enabled.
   • Database: The MongoDB database whose collections you want to query (for example, sample_mflix). Collections in that database appear as tables.
   • Username: The database user
   • Password: The database user password
   • SRV connection: Use a mongodb+srv connection and discover hosts through DNS
   • TLS: Encrypt the connection with TLS. Atlas SRV connections already use TLS, so you typically leave this off unless you need a custom CA.
   • Authentication source (optional): Database where the user is defined, often admin
   • CA certificate (optional): Custom CA used to verify the MongoDB server
5. Click Save

Once added, collections from the connected database show up as tables in the catalog browser. You can query them with DuckDB SQL:

Copy
SELECT * FROM mongo.sample_mflix.comments LIMIT 100;

If the catalog is named mongo and the database is sample_mflix, the fully qualified table name is mongo.sample_mflix.comments.

Atlas mapping