SQL multi-table query guidance - sql

Question

I have the following query:
SELECT
_RES_COLL_EVM00012.MachineID,
_RES_COLL_EVM00012.Name,
v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0,
v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0,
v_GS_NETWORK_ADAPTER_CONFIGUR.TimeStamp,
v_GS_NETWORK_ADAPTER_CONFIGUR.RevisionID
FROM
_RES_COLL_EVM00012
LEFT JOIN v_GS_NETWORK_ADAPTER_CONFIGUR
ON _RES_COLL_EVM00012.MachineID = v_GS_NETWORK_ADAPTER_CONFIGUR.ResourceID
WHERE
v_GS_NETWORK_ADAPTER_CONFIGUR.IPEnabled0 = 1
AND v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0 != '0.0.0.0'
AND v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0 IS NOT NULL
AND v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0 != '0.0.0.0'
AND v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0 IS NOT NULL
ORDER BY
_RES_COLL_EVM00012.Name ASC,
v_GS_NETWORK_ADAPTER_CONFIGUR.TimeStamp DESC,
v_GS_NETWORK_ADAPTER_CONFIGUR.RevisionID DESC
Which returns something like the following:
MachineID Name IPAddress0 DefaultGatewayIP0 TimeStamp RevisionID
16777323 CTNB21 192.168.17.134 192.168.17.254 9/09/2013 13:07:11 8
16777323 CTNB21 192.168.17.143 192.168.17.254 9/09/2013 13:07:11 6
16777585 CTNB26 192.168.16.106 192.168.16.254 28/10/2013 22:39:55 33
16777585 CTNB26 192.168.16.116 192.168.16.254 28/10/2013 22:39:55 27
Obviously ResourceID is not unique in the table v_GS_NETWORK_ADAPTER_CONFIGUR. What I need to do is display every row from the table _RES_COLL_EVM00012 along with a SINGLE row for each from v_GS_NETWORK_ADAPTER_CONFIGUR.
The row selected from v_GS_NETWORK_ADAPTER_CONFIGUR should be the one with the most recent TimeStamp and the greatest RevisionID.
Note also I do not actually want to select MachineID, TimeStamp or RevisionID, I have just done so to help better explain my request.
One more thing, if a row does not exist in v_GS_NETWORK_ADAPTER_CONFIGUR with a match for the MachineID/ResourceID, I still need to output the Name but with blank values for IPAddress0 and DefaultGatewayIP0
So to clarify I would like the example result set to look like this instead:
Name IPAddress0 DefaultGatewayIP0
CTNB21 192.168.17.134 192.168.17.254
CTNB26 192.168.16.106 192.168.16.254

Answer 1

Try this:
SELECT
--_RES_COLL_EVM00012.MachineID,
_RES_COLL_EVM00012.Name,
ISNULL(v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0,'') as IPAddress0,
ISNULL(v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0,'') as DefaultIPGateway0
--v_GS_NETWORK_ADAPTER_CONFIGUR.TimeStamp,
--v_GS_NETWORK_ADAPTER_CONFIGUR.RevisionID
FROM
_RES_COLL_EVM00012
LEFT JOIN v_GS_NETWORK_ADAPTER_CONFIGUR
ON _RES_COLL_EVM00012.MachineID = v_GS_NETWORK_ADAPTER_CONFIGUR.ResourceID
LEFT JOIN (SELECT a.ResourceID,a.RevisionID, MAX(a.TimeStamp) as TimeStamp
FROM v_GS_NETWORK_ADAPTER_CONFIGUR a
join (SELECT ResourceID, MAX(RevisionID) as RevisionID
FROM v_GS_NETWORK_ADAPTER_CONFIGUR
GROUP BY ResourceID) b
ON a.ResourceID=b.ResourceID
GROUP BY a.ResourceID,a.RevisionID
)c
ON v_GS_NETWORK_ADAPTER_CONFIGUR.ResourceID=c.ResourceID
AND v_GS_NETWORK_ADAPTER_CONFIGUR.RevisionID=c.RevisionID
AND v_GS_NETWORK_ADAPTER_CONFIGUR.TimeStamp=c.TimeStamp
WHERE
c.RevisionID IS NOT NULL
ORDER BY
_RES_COLL_EVM00012.Name ASC,
v_GS_NETWORK_ADAPTER_CONFIGUR.TimeStamp DESC,
v_GS_NETWORK_ADAPTER_CONFIGUR.RevisionID DESC

Answer 2

Use DENSE_RANK()OVER(PARTITION BY RevisionID,TimeStamp ORDER BY RevisionID,TimeStamp DESC) in select statement as below.
SELECT *
FROM (SELECT _RES_COLL_EVM00012.MachineID,
_RES_COLL_EVM00012.Name,
v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0,
v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0,
v_GS_NETWORK_ADAPTER_CONFIGUR.TimeStamp,
v_GS_NETWORK_ADAPTER_CONFIGUR.RevisionID,
DENSE_RANK() OVER (PARTITION BY RevisionID, TimeStamp
ORDER BY RevisionID, TimeStamp DESC) RowID
FROM _RES_COLL_EVM00012
LEFT JOIN v_GS_NETWORK_ADAPTER_CONFIGUR
ON _RES_COLL_EVM00012.MachineID = v_GS_NETWORK_ADAPTER_CONFIGUR.ResourceID
WHERE v_GS_NETWORK_ADAPTER_CONFIGUR.IPEnabled0 = 1
AND v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0 != '0.0.0.0'
AND v_GS_NETWORK_ADAPTER_CONFIGUR.IPAddress0 IS NOT NULL
AND v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0 != '0.0.0.0'
AND v_GS_NETWORK_ADAPTER_CONFIGUR.DefaultIPGateway0 IS NOT NULL
) XYZ
WHERE XYZ.RowID = 1
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