Question

I have a query that returns a row of data for each country as well as the other related information. The query (with everything not relevant removed) looks like so:

SELECT a.*, ROW_NUMBER() OVER(ORDER BY a.DateSubmitted) As RowNumber, c.CountryName FROM     Table1 a
inner join Table2 b
on a.id = b.id
inner join Table3 c on c.countrycode = b.countrycode

This returns the row number for each row like so:

    ID  User        Country     RowNumber
    8   testtest    BANGLADESH  1
    14  testtest    ANGOLA      2
    14  testtest    AUSTRALIA   3
    14  testtest    BANGLADESH  4
    15  testera1    BELIZE      5
    15  testera1    CONGO       6

However, I need to return a 0 or 1 for each unique ID and not for each row in the main statement I already have. So what I would like to have is the following:

    ID  User        Country     RowNumber
    8   testtest    BANGLADESH  0
    14  testtest    ANGOLA      1
    14  testtest    AUSTRALIA   1
    14  testtest    BANGLADESH  1
    15  testera1    BELIZE      0
    15  testera1    CONGO       0

I’m pretty weak at SQL and I’m finally making a conscious attempt to improve it, so thank you very much for your help.

Answer 1

DENSE_RANK() can be used to give each id a different value, but with all occurances of the same id having the same value. Do % 2 to any number and you get 0 or 1…

SELECT
  a.*,
  c.CountryName
  ROW_NUMBER() OVER(ORDER BY a.DateSubmitted)  As RowNumber,
  (DENSE_RANK() OVER (ORDER BY a.ID) - 1) % 2  As StrangeBinaryFlag
FROM
  Table1 a
INNER JOIN
  Table2 b
    ON a.id = b.id
INNER JOIN
  Table3 c
    ON c.countrycode = b.countrycode