SQL Selecting “Window” Around Particular Row

Question

It\'s quite possible a question like this has been asked before, but I can\'t think of the terms to search for.

I\'m working on a photo gallery application, and want

Answer 1

This is standard "Row ordering" problem... If your database has rowId capability you can use that, otherwise you need a subquery that counts the numnber of rows with Ids less than the id of the current row... like this:

-- asssuming @Id is value of id in the "middle"

 Select *  From Photos P
 Where (Select Count(*) From Photos
         Where id <= P.Id)
     Between (Select Count(*) From Photos
              Where id < @Id) - 4
        And  (Select Count(*) From Photos
              Where id < @Id) + 4

As a comment raised the album issue you would want to add album predicate to each subquery

   Select *  From Photos P
   Where (Select Count(*) From Photos
          Where album = @album
            And id <= P.Id)
     Between (Select Case When Count(*) < 4 
                      Then 4 Else Count(*) End
              From Photos
              Where album = @album
                 And id < @Id) - 4
        And  (Select Case When Count(*) < 4 
                      Then 4 Else Count(*) End
              From Photos
              Where album = @album
                  And id < @Id) + 4