read_mongodb

Read data from an arbitrary MongoDB collection. The collection does not have to be a known data source to GlareDB.

If you have multiple collections in one MongoDB deployment or are regularly using the same MongoDB data source, consider setting up a MongoDB data source.

Syntax

read_mongodb(<connection_str>, <database>, <collection>)

Field	Description
connection_str	A MongoDB connection string.
database	The name of the database.
collection	The name of the collection.

Examples

In the following example, a ‘users’ collection is queryed.

SELECT mdb.* FROM read_mongodb(
  'protocol=mongodb+srv, user=mdb_user, password=mdb_user_password',
  'mdbDatabaseName',
  'collectionName'
) AS mdb;

This exposes the fields from the MongoDB collection as a collection of fields with the mdb. prefix in a SQL query. Select an alternate prefix, or no prefix as you see fit.

Behavior

GlareDB samples up to 100 documents from the MongoDB collection, or less for smaller collections, building a schema that has the sum of all fields in the observed documents. Follow this issue for discussion of changes to schema inference for MongoDB data sources.