CoolaSQL provides the ability to run server side join. Server side join is useful when you need to either join two or more queries, or Journey Analytics and a custom table.

CoolaSQL supports the following JOIN types:

• JOIN
• INNER JOIN
• LEFT JOIN
• LEFT OUTER JOIN
• RIGHT JOIN
• RIGHT OUTER JOIN

Note: Make sure to provide aliases to all data columns in the top select when performing a join.

Example: Using INNER JOIN

SELECT a.ip_country AS country
    ,a.sessions AS current_week_sessions
    ,b.sessions AS previous_week_sessions
FROM (
    SELECT ip_country
        ,count(session_id) AS sessions
    FROM cooladata
    WHERE date_range(CURRENT WEEK)
    GROUP BY ip_country
    ) a
INNER JOIN (
    SELECT ip_country
        ,count(session_id) AS sessions
    FROM cooladata
    WHERE date_range(PREVIOUS WEEK)
    GROUP BY ip_country
    ) b ON a.ip_country = b.ip_country