SQL Syntax 1

[jchewsmith]

I am trying to update a field with a sequential number based on a order#. I only want to the number to increase in value when the order# changes.

Declare field at 999-000 add one every time the Order No changes

Order No Field to Update
123 999-001
123 999-001
123 999-001
456 999-002
456 999-002
789 999-003
234 999-004
234 999-004
345 999-005

 

[JarlH]

Use a correlated sub-query to count distinct OrderNo's up to this row's OrderNo.

update tablename t1
    set toUpdate = (select count(distinct order) from tablename t2
                    where t2.OrderNo <= t1.OrderNo)