Avoid third table multiplying results - sql

Question

I have three tables.
Defect: Main table used to store defects found.
FollowUp: Table that stores followups to a specific Defect.
Defect_Attach: Related table used all photo attachments for Defects and FollowUps.
How can I get dates for all photo attachments?
Some of these photos were taken for a defect, then at a later date, more photos were related to the defect during a followup.
The results I'm trying to get would look something like this:
or
So far my query looks like this:
SELECT d.GUID
,p.ATTACHMENTID
,p.REL_OBJECTID
,p.CONTENT_TYPE
,p.ATT_NAME
,p.DATA_SIZE
,d.DateObserved as 'Defect Date'
--,f.DateObserved as 'FollowUp Date'
FROM [ECIMUSR].[DEFECT__ATTACH] p
LEFT OUTER JOIN ECIMUSR.DEFECT d on d.ObjectID = p.REL_OBJECTID
--LEFT JOIN ECIMUSR.FOLLOWUP f on f.DefectGUID = d.GUID
WHERE
d.GUID = '{E511EA70-F5E5-11E4-8189-6C3BE50ED71F}'
ORDER BY [Defect Date]
But as soon as I try joining my third table (FOLLOWUP), my results multiply.
UPDATE:
Results:
SELECT p.ATT_NAME
,d.DateObserved as 'Defect Date'
--,f.DateObserved as 'FollowUp Date'
FROM [ECIMUSR].[DEFECT__ATTACH] p
LEFT OUTER JOIN ECIMUSR.DEFECT d on d.ObjectID = p.REL_OBJECTID
--LEFT JOIN ECIMUSR.FOLLOWUP f on f.DefectGUID = d.GUID
WHERE
d.GUID = '{E511EA70-F5E5-11E4-8189-6C3BE50ED71F}'
ORDER BY [Defect Date]
Joining THIRD Table:
SELECT p.ATT_NAME
,d.DateObserved as 'Defect Date'
,f.DateObserved as 'FollowUp Date'
FROM [ECIMUSR].[DEFECT__ATTACH] p
LEFT OUTER JOIN ECIMUSR.DEFECT d on d.ObjectID = p.REL_OBJECTID
LEFT JOIN ECIMUSR.FOLLOWUP f on f.DefectGUID = d.GUID
WHERE
d.GUID = '{E511EA70-F5E5-11E4-8189-6C3BE50ED71F}'
ORDER BY [Defect Date]

Answer 1

SELECT
d.DateObserved AS defect_date,
p.ATT_NAME AS photo_name,
f.DateObserved AS follow_up_date
FROM
(
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY REL_OBJECTID
ORDER BY ATT_NAME) AS ordinal
FROM
ECIMUSR.DEFECT__ATTACH
)
p
FULL OUTER JOIN
(
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY DefectGUID
ORDER BY DateObserved) AS ordinal
FROM
ECIMUSR.FOLLOWUP
)
f
ON f.DefectGUID = p.REL_OBJECTID
AND f.ordinal = p.ordinal
RIGHT JOIN
ECIMUSR.DEFECT d
ON d.ObjectID = COALESCE(f.DefectGUID, p.REL_OBJECTID)
Would give something like...
defect_date | photo_name | follow_up_date
-------------+-----------------------------+----------------
2014-12-19 | photo1.jpg | 2015-01-16
2014-12-19 | PhotoFollowUp1_20150117.jpg | 2015-03-19
2014-12-19 | PhotoFollowUp1_20150324.jpg | 2015-04-17
2014-12-19 | PhotoFollowUp1_20150417.jpg | NULL
2014-12-19 | PhotoFollowUp2_20150324.jpg | NULL
The photo names and the follow up dates have nothing to do with each others. they're just in alphabetical order with gaps if one list is longer than the other.