Question

I want to filter the data in my SQL so that I only have the latest row for each thickness where the IsReady field is true.

EDIT: I’m using MSSQL 2008 server for all who need to know

My data is like this:

+--+----------+-----------+----------+-------+
|ID|SupplierID|ThicknessID|DateTime  |IsReady|
+--+----------+-----------+----------+-------+
|01|1         |1          |01/01/1990|1      |
|02|1         |1          |01/01/2012|0      |
|03|1         |2          |01/01/1990|1      |
|04|1         |2          |01/01/2012|1      |

Based off this data provided, the SQL code should return the following:

+--+----------+-----------+----------+-------+
|ID|SupplierID|ThicknessID|DateTime  |IsReady|
+--+----------+-----------+----------+-------+
|01|1         |1          |01/01/1990|1      |
|04|1         |2          |01/01/2012|1      |

Hope this is enough information for you to understand, if not just comment

Answer 1

SELECT t.*
FROM Table t
WHERE IsReady=1
AND t.ID=(SELECT TOP 1 t2.ID
          FROM Table t2
          WHERE t2.IsReady=1
          AND t.ThicknessID=t2.ThicknessID
          ORDER BY DateTime DESC)