Question

I’m quite new in SQl This is my requirement.

TableA 
operation route measurement
A         No    200
A         Yes   300
B         No    400
B         Yes   500

I want this as result

Operation MeasurementNo  MeasurementYes  MeasureDifference
A         200            300             100
B         400            500             100

So the operation field has to be grouped. At the same time the two values of the measurement of the operation have to be merged to one row.

The MeasureDifference = MeasurementYes - MeasurementNo.

It looks not that difficult too achieve with SQL, but I’m just a newbee. Any help is appreciated.

Answer 1

Or use grouping and conditional aggregation:

SELECT
  operation,
  SUM(CASE route WHEN 'No'  THEN measurement END) AS MeasurementNo,
  SUM(CASE route WHEN 'Yes' THEN measurement END) AS MeasurementYes,
  SUM(CASE route WHEN 'Yes' THEN measurement END)
  - SUM(CASE route WHEN 'No'  THEN measurement END) AS MeasurementDifference
FROM atable t
GROUP BY
  operation