Update with inner join not working in db2 - sql

Question

I have a structure similar to a working query in mysql that is an update based on an inner join with counts
update schema.daily_totals ct
inner JOIN (
SELECT
COUNT (*) AS contacted,
SUM( CASE WHEN f.follow_up_date BETWEEN CURRENT_DATE AND CURRENT_DATE + 7 DAYS THEN 1 ELSE 0 END ) AS potentials,
CAST (ROUND((SUM( CASE WHEN f.follow_up_date BETWEEN CURRENT_DATE AND CURRENT_DATE + 7 DAYS THEN 1.0 ELSE 0 END )/ COUNT (*)) * 100.00, 2) AS DECIMAL (12, 2)) AS PERCENT,
u.user_id as userID,
FROM schema.users u
INNER JOIN schema.notated n
ON n.user_identifier = u.user_id
INNER JOIN schema.comms m
ON n.comms_ID = m.comms_ID
LEFT JOIN schema.FDates f
ON f.dNumber = n.dNumber
WHERE code <> 'none'
AND n.created_at >= CURRENT_DATE - 1 DAYS
GROUP BY u.user_id, u.first_name, u.last_name
) as cu
on cu.userID = ct.ext_id
set ct.contacted_contacted = cu.contacted,
ct.percent_up_to_date = cu.percent
where ct.date_of_report >= current_date;
But it won't run, it seems to break around the final 'on' where I'm joining on the subquery.
Am I not able to run this in db2 at all?

Answer 1

Use MERGE statement instead.
MERGE INTO schema.daily_totals ct
USING (
SELECT
COUNT (*) AS contacted,
SUM( CASE WHEN f.follow_up_date BETWEEN CURRENT_DATE AND CURRENT_DATE + 7 DAYS THEN 1 ELSE 0 END ) AS potentials,
CAST (ROUND((SUM( CASE WHEN f.follow_up_date BETWEEN CURRENT_DATE AND CURRENT_DATE + 7 DAYS THEN 1.0 ELSE 0 END )/ COUNT (*)) * 100.00, 2) AS DECIMAL (12, 2)) AS PERCENT,
u.user_id as userID,
FROM schema.users u
INNER JOIN schema.notated n
ON n.user_identifier = u.user_id
INNER JOIN schema.comms m
ON n.comms_ID = m.comms_ID
LEFT JOIN schema.FDates f
ON f.dNumber = n.dNumber
WHERE code <> 'none'
AND n.created_at >= CURRENT_DATE - 1 DAYS
GROUP BY u.user_id, u.first_name, u.last_name
) as cu
on cu.userID = ct.ext_id and ct.date_of_report >= current_date
WHEN MATCHED THEN UPDATE
set contacted_contacted = cu.contacted, percent_up_to_date = cu.percent;