Remove Duplicates while Merging values - sql

Question

How can I remove duplicates and merge Account Types?
I have a call log that reports duplicate phones based on Account Type.
For example:
Telephone | Account Type
304-555-6666 | R
304-555-6666 | C
I know how to remove duplicate Telephones using RANK\MAXCOUNT
But before removing duplicates I need to reset the Account Type to “B” is the duplicates have multiple account types.
In the example the surviving duplicate would be:
Telephone | Account Type
304-555-6666 | B
Warning, it is not guaranteed that duplicate phones have multiple Account Types.
Example:
Telephone | Account Type
999-888-6666 | R
999-888-6666 | R
Therefore the surviving duplicate should be:
Telephone | Account Type
999-888-6666 | R
How can I remove duplicates and reset the account type at the same time?
--
-- Remove Duplicate Recordings
--
SELECT * FROM (
SELECT i.dateofcall ,
i.recordingfile ,
i.telephone ,
s.accounttype ,
ROW_NUMBER() OVER (PARTITION BY i.telephone ORDER BY i.dateofcall DESC) AS 'RANK' ,
COUNT(i.telephone) OVER (PARTITION BY i.telephone) AS 'MAXCOUNT'
FROM #myactions i
LEFT JOIN #myphone s ON s.interactionID = i.Interactionid
) x
WHERE [RANK] = [MAXCOUNT]

Answer 1

SELECT * FROM (
SELECT i.dateofcall ,
i.recordingfile ,
i.telephone ,
s.accounttype ,
ROW_NUMBER() OVER (PARTITION BY i.telephone ORDER BY i.dateofcall DESC) AS 'RANK' ,
COUNT(i.telephone) OVER (PARTITION BY i.telephone) AS 'MAXCOUNT',
DENSE_RANK() OVER ( PARTITION BY i.telephone ORDER BY s.accounttype DESC ) AS 'ContPhone'
FROM #myactions i
LEFT JOIN #myphone s ON s.interactionID = i.Interactionid
) x
WHERE [RANK] = [MAXCOUNT]

Answer 2

Try this?
select
x.dateofcall
, x.recordingfile
, x.telephone
, case when count(*) > 2 then 'B' else max(x.accounttype) end accounttype
(
select
i.dateofcall
, i.recordingfile
, i.telephone
, s.accounttype
from
#myactions i
LEFT JOIN #myphone s ON s.interactionID = i.Interactionid
group by
i.dateofcall
, i.recordingfile
, i.telephone
, s.accounttype
) x
group by
x.dateofcall
, x.recordingfile
, x.telephone

Answer 3

Basically you need to put your business check in a case statement outside.
EDIT: I've also added the logic for B, R and C. Also done a sql fiddle- link to fiddle -http://sqlfiddle.com/#!6/b5ef5/7
SELECT
x.dateofcall,
x.recordingfile,
x.telephone,
COALESCE(
CASE WHEN x.maxcount>1 AND value>x.maxcount AND value<(2*x.maxcount) THEN 'B' ELSE NULL END,
CASE WHEN x.maxcount>1 AND value= (2*x.maxcount) THEN 'C' ELSE NULL END,
CASE WHEN x.maxcount>1 AND value= x.maxcount THEN 'R' ELSE NULL END,
x.accounttype ) as accounttype,
x.rank,
x.maxcount
FROM (
SELECT i.dateofcall ,
i.recordingfile ,
i.telephone ,
s.accounttype ,
ROW_NUMBER() OVER (PARTITION BY i.telephone ORDER BY i.dateofcall DESC) AS 'RANK' ,
COUNT(i.telephone) OVER (PARTITION BY i.telephone) AS 'MAXCOUNT',
SUM(CASE WHEN s.accounttype LIKE 'R' THEN 1 ELSE 2 END) OVER (PARTITION BY i.telephone) as Value
FROM
myactions i LEFT JOIN myphone s
ON s.interactionID = i.Interactionid
) x
WHERE [RANK] = [MAXCOUNT]