Question

I have two select queries that I need to combine….

  SELECT [DatapointID]
  ,[AssetID]
  ,[DatapointID]
  ,[SourceTag]
  ,'-' + [TimeStep] + [TimeStepValue] AS TimeStep
  ,[DataRetrievalInterval] + [DataRetrievalIntervalValue] AS [RetInterval]
  ,NULL AS DatapointDate
  ,NULL AS DatapointValue
  ,0 As DataFlagID
  ,DateADD(-1, d @SearchDateEnd) + @SearchTimeEnd DateDataGrabbed
  ,GetDate() DateTimeAddedtoDB
FROM [dbo].[tblTSS_Assets_Datapoints]
Where AssetID = 204     


Select DatapointDate, SUM(DataPointValue) as DataPointValue From @temp
GROUP BY DatapointDate
ORDER BY DatapointDate

The first select query is what I want the end result to be however instead of NULL As the DatapointDate and DatapointValue I want the values from the @temp

How can I do this?

Answer 1

A join will combine the values from the two tables. In this case, there is not an obvious join key, so you would have a cross join:

SELECT [DatapointID], [AssetID], [DatapointID], [SourceTag],
       '-' + [TimeStep] + [TimeStepValue] AS TimeStep,
       [DataRetrievalInterval] + [DataRetrievalIntervalValue] AS [RetInterval],
       d.DatePointDate, d.DatapointValue,
       0 As DataFlagID,
       DateADD(-1, d @SearchDateEnd) + @SearchTimeEnd DateDataGrabbed,
       GetDate() DateTimeAddedtoDB
FROM [dbo].[tblTSS_Assets_Datapoints] cross join
     (Select DatapointDate, SUM(DataPointValue) as DataPointValue From @temp
      GROUP BY DatapointDate
     ) d
Where AssetID = 204  

This, however, will multiply the number of rows, with one for each date. Do you have a specific rule for choosing one of the rows?