SELECT DISTINCT STATEMENT - sql

Question

For some reason, my query is returning dup rows. I am trying to create a SELECT DISTINCT query. Can someone please tell me what is wrong with my query?
SELECT DISTINCT
PT_AGCY_DTL.MLM_AGCY_NBR AS AgencyID
, AGENCY.ORG_NM AS Agency
, AGCY_ADDR.CTY_NM as AgencyCity
, AGCY_ADDR.ST_PRVN_CDE_CID as AgencyST
, AG_AGCY_CNTCT.AGCY_CNTCT_ID as ContactID
, AG_AGCY_CNTCT.CNTCT_DT AS ContactDt
, AG_AGCY_CNTCT.AGCY_RESULTS_TXT AS AgencyResults
, AG_AGCY_CNTCT.GEN_OVERVIEW_TXT AS GeneralOverview
, AG_AGCY_CNTCT.NB_RNWL_BUS_DISCUSSION_TXT AS NewAndRenewalBusinessDiscussions
, AG_AGCY_CNTCT.NB_RNWL_BUS_DISCUSSION_TXT AS NewAndRenewalBusinessDiscussions
, AG_AGCY_CNTCT.MKT_INTELLIGENCE_TXT AS MarketIntelligence
, AG_AGCY_CNTCT.AGCY_PERSONNEL_CHG_TXT AS AgencyPersonnelChanges
, AG_AGCY_CNTCT.MM_ISSUE_TXT AS MyMonitorIssues
, AG_AGCY_CNTCT.UW_CLM_ISSUE_TXT AS UnderwritingClaimIssues
, AG_AGCY_CNTCT.FOLLOW_UP_ITEM_TXT AS FollowUpActionItems
, AG_AGCY_CNTCT.NXT_CNTCT_DT AS NextScheduledVisitDate
, CONTACT_TYPE.CODE_NM AS ContactType
, CONVERT(VARCHAR, AG_AGCY_CNTCT.CNTCT_DT,101) + ' - ' + CONTACT_TYPE.CODE_NM AS ContactDtType
, AG_AGCY_CNTCT.CNTCT_DESC AS ContactDetails
, CASE
WHEN PRODUCER.LST_NM IS NULL THEN ' '
ELSE LTRIM(RTRIM(PRODUCER.FRST_NM)) + ' ' + LTRIM(RTRIM(PRODUCER.LST_NM)) END AS Producers
, CASE
WHEN MLM_EMPL.LST_NM IS NULL THEN ' '
ELSE LTRIM(RTRIM(MLM_EMPL.FRST_NM)) + ' ' + LTRIM(RTRIM(MLM_EMPL.LST_NM)) END AS Employees
, CASE
WHEN PROD_CAT.CODE_NM IS NULL THEN ' '
ELSE LTRIM(RTRIM(PROD_CAT.CODE_NM)) END AS ProductCategory
FROM
AG_AGCY_CNTCT
INNER JOIN PT_AGCY_DTL
ON AG_AGCY_CNTCT.AGCY_PID = PT_AGCY_DTL.PARTY_ID
INNER JOIN PT_PARTY AS AGENCY
ON AGENCY.PARTY_ID = AG_AGCY_CNTCT.AGCY_PID
LEFT OUTER JOIN PT_PARTY_ADDR AS AGCY_ADDR
ON AGCY_ADDR.PARTY_ID = AG_AGCY_CNTCT.AGCY_PID
INNER JOIN CD_CODE AS CONTACT_TYPE
ON CONTACT_TYPE.CODE_ID = AG_AGCY_CNTCT.CNTCT_TYP_CID
LEFT OUTER JOIN AG_AGCY_CNTCT_PRDCR_RLTNSHP
ON AG_AGCY_CNTCT_PRDCR_RLTNSHP.AGCY_CNTCT_ID = AG_AGCY_CNTCT.AGCY_CNTCT_ID
LEFT OUTER JOIN PT_PARTY AS PRODUCER
ON PRODUCER.PARTY_ID = AG_AGCY_CNTCT_PRDCR_RLTNSHP.PRDCR_PID
LEFT OUTER JOIN AG_AGCY_CNTCT_MLM_EMPL_RLTNSHP
ON AG_AGCY_CNTCT_MLM_EMPL_RLTNSHP.AGCY_CNTCT_ID = AG_AGCY_CNTCT.AGCY_CNTCT_ID
LEFT OUTER JOIN PT_PARTY AS MLM_EMPL
ON MLM_EMPL.PARTY_ID = AG_AGCY_CNTCT_MLM_EMPL_RLTNSHP.MLM_EMPL_PID
LEFT OUTER JOIN AG_AGCY_CNTCT_PROD_CAT_TYP_RLTNSHP
ON AG_AGCY_CNTCT_PROD_CAT_TYP_RLTNSHP.AGCY_CNTCT_ID = AG_AGCY_CNTCT.AGCY_CNTCT_ID
LEFT OUTER JOIN CD_CODE AS PROD_CAT
ON PROD_CAT.CODE_ID = AG_AGCY_CNTCT_PROD_CAT_TYP_RLTNSHP.PROD_CAT_TYP_CID
AND AGCY_ADDR.ADDR_TYP_CID = '30' -- business address
AND AGCY_ADDR.REC_STS_TYP_CID = 'A' -- active
WHERE
PT_AGCY_DTL.MLM_AGCY_NBR ='4759' --#AgencyID (this is the FILTER)
ORDER BY ContactDt DESC, ContactID DESC

Answer 1

You don't specify, but I suspect you are under the impression that the following rows are duplicate:
t1.col1 | t1.col2 | t2.col1
--------------------------------
1 | 1 | 1
1 | 1 | 2
This is not the case. As was mentioned in the comments, DISTINCT is applied to all columns you are selecting. You can see there are two different combinations of values, hence two rows will be returned. Some people will use an aggregate function and a group by to get around this. Example:
SELECT t1.col1, t1.col2, MAX(t2.col1)
FROM table1 t1
INNER JOIN table2 t2
on t1.whatever = t2.whatever
GROUP BY t1.col1, t1.col2
This would only return the second row. If you are doing this be sure that you understand that you are excluding information in order to force the appearance of a distinct set of records.