Question

Basically, I want have two separate SQL queries, but I want them to be displayed in the same result set. However, the first query returns several columns and the second query only returns one column.

If I want the results from the second query to simply be added on as an additional column to the results from the first query, how do I do this?

Query 1:

SELECT cr.COMMUNICATION_ID, cr.CONSUMER_ID, cr.ACTION_LOG_ID, cal.CONSUMER_ID, cal.TIPS_AMOUNT, cal.LAST_MOD_TIME
FROM COMMUNICATION_RELEVANCE AS cr
JOIN consumer_action_log AS cal
ON cr.ACTION_LOG_ID=cal.ACTION_LOG_ID;

QUERY 2:

SELECT AVG(TIPS_AMOUNT) AS AVG_TIPS
FROM CONSUMER_ACTION_LOG
JOIN COMMUNICATION_RELEVANCE
ON CONSUMER_ACTION_LOG.SENDER_CONSUMER_ID=COMMUNICATION_RElEVANCE.consumer_id;

Basically, I want a UNION, but for queries with different number of columns.

Answer 1

I think you actually want to add one column, not one row as the other answers suggest

SELECT cr.COMMUNICATION_ID, cr.CONSUMER_ID, cr.ACTION_LOG_ID,
       cal.CONSUMER_ID, cal.TIPS_AMOUNT, cal.LAST_MOD_TIME,
       SINGLETON.AVG_TIPS
FROM COMMUNICATION_RELEVANCE AS cr
JOIN consumer_action_log AS cal ON cr.ACTION_LOG_ID=cal.ACTION_LOG_ID
CROSS JOIN
(
    SELECT AVG(TIPS_AMOUNT) AS AVG_TIPS
    FROM CONSUMER_ACTION_LOG
    JOIN COMMUNICATION_RELEVANCE
    ON CONSUMER_ACTION_LOG.SENDER_CONSUMER_ID=COMMUNICATION_RElEVANCE.consumer_id
) SINGLETON

The trick is that you join to the query that produces the single row, single column AVG value.