Question

I have a table like these:

STATE      code     company   rate 
----------------------------------
TX          SD      1         0.5
TX          SD      2         0.5
TX          SD      3         0.7
TX          SD      4         0.5
..........

I need to verify that is the rate same under the same state and same code.

I consider to join the table by itself and get the rate 1 and rate2 , then can use case when to compare the two columns

Something like this:

CASE WHEN COLUMN1 = COLUMN2 THEN '1' ELSE '0' END AS MyDesiredResult

I do not know does it work? How can I can join the table?

Basically, I need a report to see if the rate is different under the same state and same code.

thanks

Answer 1

this will show you the offending state/code combinations:

select state, code, min(rate) min_rate, max(rate) max_rate
  from myTable
 group by state, code
having min(rate) != max(rate)

You can process further to find how many rows each rate have. for example using a CTE, but I left it as an exercise for the reader.