I would like to convert the following query:
SELECT
request.requestId
FROM
request
LEFT OUTER JOIN incident ON incident.requestId = request.requestId
You have the (+) on the wrong side, it should be:
SELECT
request.requestId
FROM
request,
incident,
changeRequest
WHERE
incident.requestId (+)= request.requestId
AND changeRequest.requestId (+)= request.requestId
BTW I assume you realse this is the old Oracle syntax? Oracle has supported ANSI joins for a long time now.