Generating SQL Permutations

Kevin Feasel

2017-02-15

T-SQL

Michael J. Swart uses a recursive common table expression and bit shifting to build a full set of permutations:

If you google “generating permutations using SQL”, you get thousands of hits. It’s an interesting problem if not very useful.
I wrote a solution recently and thought I’d share it. If you’re keen, try tackling it yourself before moving on.

Click through for the script.  It’s an interesting approach and might be worth playing a round of code golf.

Related Posts

Your Reminder Not To MERGE

Kevin Wilkie points out the numerous problems with the MERGE operator: Now, when I last posted, I’m sure you thought I was done talking about the MERGE statement. You are so wrong, compadre! One more post is absolutely needed! There are a few issues with the MERGE statement. Well, as of this writing, there are 361 possible issues according […]

Read More

CROSS APPLY Replacing REPLACE

Bert Wagner shows off a good use of the APPLY operator: Here we only have 4 nested REPLACE functions. My shameful record is 29. I’m not proud of it, but sometimes it’s the only way to get things done. Not only are these nested REPLACE() functions difficult to write, but they are difficult to read […]

Read More

Categories

February 2017
MTWTFSS
« Jan Mar »
 12345
6789101112
13141516171819
20212223242526
2728