> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/build/mongodb.md).

# Find documents with MongoDB in Duaer

In Duaer, MongoDB defaults to Resource Document and Operation Find. Set Collection. Query (JSON Format) defaults to {}. You need a mongoDb credential.
## Find documents

1. Create a mongoDb credential.
2. Search for MongoDB, connect it after the previous node, and select that credential.
3. Leave Resource on Document and Operation on Find.
4. Set Collection.
5. Query (JSON Format) defaults to {} (match all). Change it to a filter JSON if needed. Select Execute step.

Under Document you also get Aggregate, Insert, Update, Delete, Find And Update, and Find And Replace.

Prefer Query Parameters ($1, $2) for dynamic values instead of embedding expressions in the query JSON.

For tabular stores, see [Read and write Postgres in Duaer](/build/postgres.md) and [Read and write MySQL in Duaer](/build/mysql.md).
## Questions

### Does MongoDB Find in Duaer limit results by default?

Limit under Options defaults to 0, which means unlimited. Set Limit in Options when you need a cap.

## Related

- [Read and write Postgres in Duaer](https://doc.duaer.com/build/postgres.md)
- [Read and write MySQL in Duaer](https://doc.duaer.com/build/mysql.md)
- [Keep rows in a Duaer data table](https://doc.duaer.com/build/data-tables.md)