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

Faster Scalar Functions In SQL Server 2019

Brent Ozar looks at improvements the SQL Server team has made to scalar functions in 2019: My database has to be in 2019 compat mode to enable Froid, the function-inlining magic. Run the same query again, and the metrics are wildly different: Runtime: 4 seconds CPU time: 4 seconds Logical reads: 3,247,991 (which still sounds bad, […]

Read More

Uncovering Complexity In SQL Objects

Michael J. Swart helps us uncover hidden complexity in database objects: The other day, Erin Stellato asked a question on twitter about the value of nested SPs. Here’s how I weighed in: I’m not a fan of nested anything. Too much hidden complexity. Code reusability leads to queries that are jack of all trades, master […]

Read More

Categories

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