Question

I want the result set of a database query to have a certain order. The information I want to order by is not contained in the database, but dynamically generated in code (so I cannot use ORDER BY).

Is there a way to sort a dataset after executing the database query? (I don’t need indexed access but only want to iterate over all records.)

Answer 1

There is a possibility that shares similarities with Jens’ answer (+1) but gets to the result in a slightly different fashion.

Given an existing table:

create table somedata (id integer, name char(20));
insert into somedata values ( 1, 'Tim' );
insert into somedata values ( 2, 'Bob' );
insert into somedata values ( 3, 'Joe' );

If you know the desired short order (either by processing the table or some query result from it), create a temp table that has some key value to match the desired rows from the original table and then the sort order data:

create table #sortorder( id integer, sortvalue integer );

Set the sortvalue field in the temp table to contain the desired order (it could be any sortable data type – doesn’t have to be integer):

insert into #sortorder values ( 1, 15 );
insert into #sortorder values ( 2, 12 );
insert into #sortorder values ( 3, 5 );

Then generate the results with a join against the table that provides the sort order:

select sd.* from somedata sd, #sortorder so 
         where sd.id = so.id
         order by so.sortvalue;