The CData JDBC Driver for Redis supports joins of multiple tables.

Joining Multiple Tables

You can join multiple tables just like you would in a relational database. Set SupportEnhancedSQL to True to execute these types of joins. The following examples use two tables: Restaurants and Zips.

The query below returns the Restaurant records that exist, if any, for each ZIP code:

SELECT z.city, r.name, r.borough, r.cuisine, r.zipcode
FROM Zips z
LEFT JOIN Restaurants r
ON r.zipcode = z._id

The query below returns records from both tables that match the join condition:

SELECT z.city, r.name, r.borough, r.cuisine, r.zipcode
FROM Restaurants r
INNER JOIN Zips z
ON r.zipcode = z._id