Lynn Pettis (1/15/2013)
Please compare the following two pieces of code:
WITH SampleData (BipolarNumbers) AS (
SELECT '1'
UNION ALL SELECT '100231-A'
UNION ALL SELECT '1003'
UNION ALL SELECT '11'
UNION ALL SELECT '11342'
UNION ALL SELECT '11342-A'
UNION ALL SELECT '12')
SELECT
BipolarNumbers
FROM SampleData
ORDER BY
CAST(LEFT(BipolarNumbers, CASE PATINDEX('%[^0-9]%', BipolarNumbers)
WHEN 0 THEN LEN(BipolarNumbers)
ELSE PATINDEX('%[^0-9]%', BipolarNumbers) - 1
END) AS INT),
substring(BipolarNumbers,CASE PATINDEX('%[^0-9]%', BipolarNumbers) WHEN 0 THEN 0 ELSE PATINDEX('%[^0-9]%', BipolarNumbers) end, CASE PATINDEX('%[^0-9]%', BipolarNumbers) WHEN 0 THEN 0 ELSE (LEN(BipolarNumbers) - PATINDEX('%[^0-9]%', BipolarNumbers)) + 1 end)
;
WITH SampleData (BipolarNumbers) AS (
SELECT '1'
UNION ALL SELECT '100231-A'
UNION ALL SELECT '1003'
UNION ALL SELECT '11'
UNION ALL SELECT '11342'
UNION ALL SELECT '11342-A'
UNION ALL SELECT '12')
SELECT BipolarNumbers
FROM SampleData
ORDER BY CAST(LEFT(BipolarNumbers
,CASE PATINDEX('%[^0-9]%', BipolarNumbers)
WHEN 0 THEN LEN(BipolarNumbers)
ELSE PATINDEX('%[^0-9]%', BipolarNumbers) - 1 END) AS INT)
The first is my modification to dwain's code and the second is his code unmodified. On my system they return two different result sets. Which one is correct?
It appears you've identified a flaw in my sort order! Shame on me!
This might fix it:
WITH SampleData (BipolarNumbers) AS (
SELECT '1'
UNION ALL SELECT '100231-A'
UNION ALL SELECT '1003'
UNION ALL SELECT '11'
UNION ALL SELECT '11342'
UNION ALL SELECT '11342-A'
UNION ALL SELECT '12')
SELECT BipolarNumbers
FROM SampleData
ORDER BY CAST(LEFT(BipolarNumbers
,CASE PATINDEX('%[^0-9]%', BipolarNumbers)
WHEN 0 THEN LEN(BipolarNumbers)
ELSE PATINDEX('%[^0-9]%', BipolarNumbers) - 1 END) AS INT)
,PATINDEX('%[^0-9]%', BipolarNumbers)
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
Need to UNPIVOT? Why not CROSS APPLY VALUES instead?[/url]
Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St