Title: Sometimes there is a shorter solution Slug: sometimes-there-is-a-shorter-solution Date: 2008-08-26 11:30:00 Author: Kartones Lang: en Tags: Databases, Development, Databases, SQL, Patterns & Practices Description: The content discusses the tendency to settle for the first solution found, using a SQL example.

Sometimes, while we're developing, we find solutions to problems that work correctly. And sometimes, we think it is the best solution and stop thinking of other possibilities.

I had a recent example few days ago, while I was coding a SQL Server stored procedure that filtered date ranges, returning elements that fit in the first four of this six available outcomes:

#1 - Wanted

#2 - Wanted

#3 - Wanted

#4 - Wanted

#5 - Unwanted

#6 - Unwanted

In order to acomplish the four first situations, this would be the SQL comparisons needed:

B1>=A1 AND B2<=A2
+
B1<=A1 AND B2<=A2
+
B1>=A1 AND B2>=A2
+
B1<=A1 AND B2>=A2

But, there's sometimes a shorter solution... Like this one:

A1<=B2 AND A2>=B1

Beautiful, don't you agree? Just by switching Bs we reduce to just one AND, covering all four desired causistics...

Sometimes we see a narrow passage (play with the lesser/greater operators) when there is more than one solution (playing with the Ax/Bx operands).