Normalize sql string combinations - sql

Question

I have the following table:
CREATE TABLE #Fruits
(
Fruits VARCHAR(100)
)
INSERT INTO #Fruits (Fruits)
VALUES ( 'banana,apple'),
('apple,banana'),
('kiwi,jackfruit'),
('jackfruit, kiwi')
banana,apple
apple,banana
kiwi,jackfruit
jackfruit, kiwi
I want to add one more column where I am taking the values separated by comma in each row and rearrange them alphabetically. I am trying to normalize the values because for my purpose apple,banana & banana,apple are the same things. And kiwi,jackfruit & jackfruit,kiwi are the same things. The output should look like the following:
Fruits Normalized_Fruits
banana,apple apple,banana
apple,banana apple,banana
kiwi,jackfruit jackfruit, kiwi
jackfruit, kiwi jackfruit, kiwi
How can I accomplish the desired result?

Answer 1

One of my biggest complaints about string_split is it lacks the ordinal position of each value. That makes situations like this one a lot easier to work with. Here is another approach to this. I am using the splitter from Jeff Moden which can be found here. There really is no need for a cursor here.
I also took the liberty of adding a GroupID column so you know which row each value belongs to once you parse them out. If the Fruits column is unique you could skip that but hard to tell for sure.
CREATE TABLE #Fruits
(
GroupID int identity
, Fruits VARCHAR(100)
)
INSERT INTO #Fruits (Fruits)
VALUES ( 'banana,apple'),
('apple,banana'),
('kiwi,jackfruit'),
('jackfruit, kiwi')
;
with SortedResults as
(
select f.GroupID
, Item = ltrim(x.Item)
, x.ItemNumber
, RowNum = ROW_NUMBER() over(partition by GroupID order by ltrim(x.Item))
from #Fruits f
cross apply dbo.DelimitedSplit8K(f.Fruits, ',') x
)
select Max(case when RowNum = 1 then Item end) + ', ' + max(case when RowNum = 2 then Item end)
from SortedResults
group by GroupID
drop table #Fruits

Answer 2

Give this a shot... I'm probably going to get nailed by non-Cursor folks, but this is what I came up with.
CREATE TABLE #Fruits
(
Fruits VARCHAR(100)
)
INSERT INTO #Fruits (Fruits)
VALUES ( 'banana,apple'),
('apple,banana'),
('kiwi,jackfruit'),
('jackfruit, kiwi')
Declare #tblFruit Table (Fruit1 varchar(100))
Declare #tblFruitSorted Table (FruitSorted varchar(100))
Declare fCursor Cursor For
Select Fruits From #Fruits
Declare #Fruitunsorted varchar(100), #FruitSorted Varchar(100) = ''
Open fCursor
Fetch Next From fCursor Into #Fruitunsorted
While ##FETCH_STATUS = 0
BEGIN
Set #FruitSorted = ''
Insert Into #tblFruit
Select * From string_split(#Fruitunsorted,',')
Update #tblFruit Set Fruit1 = Ltrim(Rtrim(Fruit1))
Select #FruitSorted = #FruitSorted + ',' + Ltrim(Rtrim(Fruit1)) From #tblFruit Order by Fruit1
Delete From #tblFruit
Insert Into #tblFruitSorted
Select Substring(#FruitSorted,2, LEN(#FruitSorted)-1)
Fetch Next From fCursor into #Fruitunsorted
END
Close fCursor
Deallocate fCursor
Select * From #tblFruitSorted
Drop Table #Fruits

Answer 3

If you're using SQL 2017 or higher:
SELECT f.Fruits
,STRING_AGG(RTRIM(LTRIM(s.[value])),',') WITHIN GROUP (ORDER BY RTRIM(LTRIM(s.[value])))
FROM #Fruits f CROSS APPLY STRING_SPLIT(f.Fruits,',') s
GROUP BY f.Fruits
;
If you're using older versions of SQL (like 2008):
IF OBJECT_ID('tempdb..#Fruits') IS NOT NULL DROP TABLE #Fruits;
CREATE TABLE #Fruits(Fruits VARCHAR(100));
INSERT INTO #Fruits (Fruits) VALUES
('banana,apple'),
('apple,banana'),
('kiwi,jackfruit'),
('jackfruit, kiwi')
;
;WITH Split AS (
SELECT DISTINCT a.Fruits,RTRIM(LTRIM(tbl.col.value ('#Value', 'nvarchar(max)'))) AS [Fruit]
FROM (SELECT f.Fruits,CONVERT(XML,'<N Value="' + REPLACE(f.Fruits,',','"></N><N Value="') + '"></N>') AS [x] FROM #Fruits f) a
CROSS APPLY a.x.nodes('//N') AS tbl (col)
)
SELECT r.Fruits,STUFF((SELECT ',' + s.Fruit FROM Split s WHERE s.Fruits = r.Fruits ORDER BY s.Fruit FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)'),1,1,'') AS [NormalizedFruits]
FROM #Fruits r
;
IF OBJECT_ID('tempdb..#Fruits') IS NOT NULL DROP TABLE #Fruits;

Answer 4

Since we're only talking about a comma delimited list of two purely alphabetic strings, I'll just throw out PARSENAME again for fun and conciseness. The trims are there because of the inconsistent use of spaces in the source data and the ELSE could be shorter, but I wanted the results to be consistent.
SELECT
Fruits
,CASE
WHEN LTRIM(RTRIM(PARSENAME(REPLACE(Fruits,',','.'),2))) > LTRIM(RTRIM(PARSENAME(REPLACE(Fruits,',','.'),1)))
THEN LTRIM(RTRIM(PARSENAME(REPLACE(Fruits,',','.'),1))) + ', ' + LTRIM(RTRIM(PARSENAME(REPLACE(Fruits,',','.'),2)))
ELSE LTRIM(RTRIM(PARSENAME(REPLACE(Fruits,',','.'),2))) + ', ' + LTRIM(RTRIM(PARSENAME(REPLACE(Fruits,',','.'),1)))
END AS Normalized_Fruits
FROM #Fruits

Answer 5

And - just for fun - one more solution calling XQuery to the rescue.
DECLARE #Fruits TABLE(Fruits VARCHAR(100));
INSERT INTO #Fruits (Fruits) VALUES
('banana,apple'),
('apple,banana'),
('kiwi,jackfruit'),
('jackfruit, kiwi');
--This is the query
SELECT f.*
,CAST('<x>' + REPLACE(REPLACE(f.Fruits,' ',''),',','</x><x>') + '</x>' AS XML)
.query('
for $f in /x/text()
order by $f
return <y>{concat(",",$f)}</y>
')
.value('substring(.,2,1000)','nvarchar(max)')
FROM #Fruits f;
By using for $f in distinct-values(/x/text()) instead of for $f in /x/text() we would supress repeating words.
In short:
Your string is converted to XML. This allows for .query(), which can deal with XQuery. This is very mighty with rather generic issues. The words are sorted and returned with a leading comma. The final substring() is needed to cut away the first leading comma.