Here's an SQL-SELECT one for you,

How would I get this data:

f1	f2
----------
0	1
1	2
2	3
2	5
1	4
4	6
6	7

Into somehting like this:

01
012
0123
0125
014
0146
01467

using a single SQL SELECT command? I can do it using DO WHILEs or SCANs and all, but am just looking for other options.