December 11, 2013 at 11:22 am
How do I write a query using the split function for the following requirement
I have a table in the following way
Identity Name Col1 Col2 Col3
1 Test1 1,2,3 200,300,400 3,4,6
2 Test2 3,4,5 300,455,600 2,3,8
I want an output in the following format
Identity Name Col1 Col2 Col3
1 Test1 1 200 3
1 Test1 2 300 4
1 Test1 3 400 6
2 Test2 3 300 2
2 Test2 4 455 3
2 Test2 5 600 8
If you see the data, first element in col1 is matched to first element in col2 and 3 after splitting the string.
December 11, 2013 at 11:31 am
I hope that you're trying to normalize your data permanently because this will give you headaches.
To split data you could use the DelimitedSplit8k. Check the article as it's really interesting.
http://www.sqlservercentral.com/articles/Tally+Table/72993/
WITH SampleData([Identity], Name, Col1, Col2, Col3) AS(
SELECT 1, 'Test1', '1,2,3', '200,300,400', '3,4,6' UNION ALL
SELECT 2, 'Test2', '3,4,5', '300,455,600', '2,3,8'
)
SELECT [Identity],
Name,
Split1.Item AS Col1,
Split2.Item AS Col2,
Split3.Item AS Col3
FROM SampleData
CROSS APPLY dbo.DelimitedSplit8K( Col1, ',') Split1
CROSS APPLY dbo.DelimitedSplit8K( Col2, ',') Split2
CROSS APPLY dbo.DelimitedSplit8K( Col3, ',') Split3
WHERE Split1.ItemNumber = Split2.ItemNumber
AND Split1.ItemNumber = Split3.ItemNumber
ORDER BY [Identity], Split1.ItemNumber
December 11, 2013 at 6:43 pm
Here's another way to do the same thing but using a single CROSS APPLY of DelimitedSplit8K.
WITH SampleData ([Identity], Name, Col1, Col2, Col3) AS
(
SELECT 1,'Test1','1,2,3','200,300,400','3,4,6'
UNION ALL SELECT 2,'Test2','3,4,5','300,455,600','2,3,8'
UNION ALL SELECT 3,'Test3','30,40,50,60','3000,4550,6000,7000','20,30,80,90'
)
SELECT [Identity], Name--, Item, ItemNumber, rn
,Col1=MAX(CASE (ItemNumber+rn-1)/rn WHEN 1 THEN Item END)
,Col2=MAX(CASE (ItemNumber+rn-1)/rn WHEN 2 THEN Item END)
,Col3=MAX(CASE (ItemNumber+rn-1)/rn WHEN 3 THEN Item END)
FROM
(
SELECT [Identity], Name, Item, ItemNumber
,rn=MAX(ItemNumber) OVER (PARTITION BY [Identity], Name)/3
FROM SampleData a
CROSS APPLY (SELECT Col1+','+Col2+','+Col3) b(Col)
CROSS APPLY dbo.DelimitedSplit8K(Col, ',') c
) a
GROUP BY [Identity], Name, (ItemNumber)%rn
ORDER BY [Identity], Name, Col1;
I do wonder what would happen to Luis's and my solutions if one of the lists in any of the columns was short a value. 😛 Not sure if that's a case you need to consider.
Well actually, I do know what would happen in my case (the results would get garbled in different ways depending on which column was missing the item). Didn't test Luis's case although I suspect it would simply be missing some rows.
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
Viewing 3 posts - 1 through 2 (of 2 total)
You must be logged in to reply to this topic. Login to reply