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Need help in framing a SQL query

Got an External View View1 and a Table A in my DB


Column details of View 1
ID1, ID2

Column details of Table A column
ID
System ID
Reconciliation ID
Instance ID

Required Result
ID1, System ID1, Reconciliation ID1, Instance ID1, ID2, System ID2, Reconciliation ID2, Instance ID2

Note:  ID1 OR  ID2 refers to ID in table A.

Let me know if you need any clarifications
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Kevin Cross
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UnifiedIS

SELECT V.ID1, A.systemID, A.ReconciliationID, A.InstanceID,
      V.ID2, V.SystemID, V.ReconciliationID, V.InstanceID
FROM View1 V
LEFT OUTER JOIN TableA A
      ON A.ID = V.ID1
LEFT OUTER JOIN TableA B
      ON B.ID = V.ID2
If you only want records where both the ID1 and ID2 values exist, then change query to use INNER JOIN versus LEFT JOIN.  As structured above, you will get where ID1 exists and ID2 doesn't and vice versus as well as where neither exist.

If you like the LEFT JOIN to get one or the other, but don't want to see where neither exists, you can add a where clause like:

WHERE COALESCE(s1.[System ID1], s2.[System ID1]) IS NOT NULL;
where does System ID2, Reconciliation ID2, Instance ID2 come from
And sorry, I just relooked and your fields are ID not ID1.
SELECT v.ID1
, s1.[System ID] AS [System ID1]
, s1.[Reconciliation ID] AS [Reconciliation ID1]
, s1.[Instance ID] AS [Instance ID1]
, v.ID2
, s2.[System ID] AS [System ID2]
, s2.[Reconciliation ID] AS [Reconciliation ID2]
, s2.[Instance ID] AS [Instance ID2]
FROM View1 v
LEFT JOIN TableA s1 ON s1.ID = v.ID1
LEFT JOIN TableA s2 ON s2.ID = v.ID2

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Clarification:

*  You have two columns in View 1 called ID1 and ID2
*  You have Table A with four columns where the first column ID can have a value equal to the value in View 1 in either ID1 or ID2, that is, for a given row in Table A its first column ID could match a row in View 1 if the Table A ID equals either ID1 or ID2 in View 1
*  You wish to output rows showing ID1 from View 1 followed by the matching System, Reconciliation, and Instance IDs from Table A and on the same output row show ID2 from View 1 followed by the matching System, Reconciliation, and Instance IDs from Table A

Is that correct?
That was a type-o on my part. Those should be aliases to identify which one of the TableA the data came from (i.e. which ID are they matching to ID1 or ID2).
The WHERE clause suggestion above would likewise be changed to this:
WHERE COALESCE(s1.[System ID], s2.[System ID]) IS NOT NULL;

Hope all that helps...
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ASKER

Fantastic response between here is my modified query to you. Let me know your suggestions

SELECT v. id_1
, s1.assetid AS assetid1
, s1.reconciliationidentity AS reconciliationidentityID1
, s1.instanceid AS instanceid1
, s1.datasetid AS datasetid1
, s1.classid AS classid1
, s1.name AS SysID1

, v. id_2
, s2.assetid AS assetid2
, s2.reconciliationidentity AS reconciliationidentityID2
, s2.instanceid AS instanceid2
, s2.datasetid AS datasetid2
, s2.classid AS classid2
, s2.name AS name2

FROM (select id_1, id_2 from aradmin.shr_association@testdb where id_1 is not NULL and id_2 is not NULL and status = 0 and id_1 like 'AST%' and id_2 like 'AST%') v
LEFT JOIN bmc_core_bmc_baseelement s1 ON substr(s1.assetid, 4) = substr(v.id_1, 4)
LEFT JOIN bmc_core_bmc_baseelement s2 ON substr(s2.assetid, 4) = substr(v.id_2, 4)