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Select from table A where in table B for one condition, but not in table B for another condition

Posted on 2011-02-24
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Last Modified: 2012-05-11
Hi All,

I've got a table that holds leads (id, firstname, surname etc)

Then I have another table which keeps a record of lead activity, i.e. when it's been viewed and assigned etc (id, person_id, lead_id, description). In this case, the description will hold the type of activity (viewed, assigned, deleted).

What I need to do is get a list of leads where they've been assigned, but not viewed. This would mean essential mean...
SELECT * FROM leads,lead_activity WHERE lead.id = lead_activity.lead_id AND lead_activity.description = 'assigned'

Somehow, in that statement I also need to do another query which checks to see if that lead is in the activity table again with the description of viewed, and if not, we need to include it in the results.

Does anyone have any ideas how to do this?
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Question by:SheppardDigital
2 Comments
 
LVL 22

Accepted Solution

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pivar earned 500 total points
ID: 34968595
Hi,

Try

select *
from leads
where exists (select 1 from lead_activity where leads.id = lead_activity.lead_id and lead_activity.description = 'assigned')
and not exists (select 1 from lead_activity where leads.id = lead_activity.lead_id and lead_activity.description = 'viewed')

/peter
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LVL 3

Expert Comment

by:LFLFM
ID: 34970036
If you just need the list of leads, I believe pivar's SQL is what you need. If you need to see the activities as well, then you just need to add the not exists clause to the sql you already had:
SELECT * FROM LEADS,LEAD_ACTIVITY
WHERE LEAD.ID = LEAD_ACTIVITY.LEAD_ID
AND LEAD_ACTIVITY.DESCRIPTION = 'assigned'
AND NOT EXISTS (SELECT 1 FROM LEAD_ACTIVITY
                WHERE LEADS.ID = LEAD_ACTIVITY.LEAD_ID
                AND LEAD_ACTIVITY.DESCRIPTION = 'viewed')

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