count and remove individual values of a single column - sql-server

Question

I have a table and the values like this
create table items_table(url varchar(max),counttotal_urls int,countduplicate_urls int,Unique_urls varchar(max),
countUnique_urls int)
insert into items_table(url) values('ht,ha,hb,ha|hc|hy')
insert into items_table(url) values('ht,hb,hb|hb|hx|hx')
insert into items_table(url) values('hz,hy,hx,hm|hm,hy')
insert into items_table(url) values('hz,hy,hx,hm|hm,hy')
I need to replace ,h with |h , for this I will use replace(url,',h','|h')
I need to count total_urls present by considering the separation '|'
I want to check or count how may duplicate url's are present
I want unique_urls to be updated in the Unique_url's column by removing the duplicates
Finally I want to count the Unique_urls which will be updated in another column
Desired output:

Answer 1

This is a bit complicated. But I tried to achieve it in Set based methodology.
Your Schema:
CREATE TABLE #items_table (
id INT identity
,url VARCHAR(max)
,counttotal_urls INT
,countduplicate_urls INT
,Unique_urls VARCHAR(max)
,countUnique_urls INT
)
INSERT INTO #items_table (url)
VALUES ('ht,ha,hb,ha|hc|hy')
INSERT INTO #items_table (url)
VALUES ('ht,hb,hb|hb|hx|hx')
INSERT INTO #items_table (url)
VALUES ('hz,hy,hx,hm|hm,hy')
INSERT INTO #items_table (url)
VALUES ('hy,hx,hm|hm,hy')
I have used several CTE's and XML methods
;WITH CTE
AS (
SELECT url
,REPLACE(',' + url, ',h', '|h') AS url2
,CAST('<M>'
+ REPLACE(REPLACE(',' + url, ',h', '|h'), '|', '</M><M>')
+ '</M>' AS XML) AS XML_FLD
FROM #items_table
)
,CTE2
AS (
SELECT url
,SUM(CASE
WHEN SUBSTRING(url2, number, 1) > '|'
THEN 1
ELSE 0
END) / 2 AS counttotal_urls
FROM CTE C
CROSS APPLY (
SELECT *
FROM master.dbo.spt_values
WHERE type = 'P'
AND number BETWEEN 1
AND LEN(C.url2)
) CA
GROUP BY url
)
,CTE3
AS (
SELECT C2.url
,C2.counttotal_urls
,SPLITS.ABC.value('.', 'varchar(MAX)') DUP_URLS
FROM CTE2 C2
INNER JOIN CTE C ON C2.url = C.url
CROSS APPLY C.XML_FLD.nodes('/M') AS SPLITS(ABC)
)
SELECT url
,counttotal_urls
,counttotal_urls - (COUNT(DISTINCT DUP_URLS) - 1) AS countduplicate_urls
,STUFF((
SELECT DISTINCT '|' + DUP_URLS
FROM CTE3 C
WHERE C3.url = C.url
FOR XML PATH('')
), 1, 1, '') AS Unique_urls
FROM CTE3 C3
GROUP BY url
,counttotal_urls
Result will be
+-------------------+-----------------+---------------------+-----------------+
| url | counttotal_urls | countduplicate_urls | Unique_urls |
+-------------------+-----------------+---------------------+-----------------+
| ht,ha,hb,ha|hc|hy | 6 | 1 | |ha|hb|hc|ht|hy |
| ht,hb,hb|hb|hx|hx | 6 | 3 | |hb|ht|hx |
| hy,hx,hm|hm,hy | 5 | 2 | |hm|hx|hy |
| hz,hy,hx,hm|hm,hy | 6 | 2 | |hm|hx|hy|hz |
+-------------------+-----------------+---------------------+-----------------+

Answer 2

You will have to create a string split table value function (Found one at aspsnippets)
as below
CREATE FUNCTION ufn_SplitString
(
#Input NVARCHAR(MAX),
#Character CHAR(1)
)
RETURNS #Output TABLE (
Item NVARCHAR(1000)
)
AS
BEGIN
DECLARE #StartIndex INT, #EndIndex INT
SET #StartIndex = 1
IF SUBSTRING(#Input, LEN(#Input) - 1, LEN(#Input)) <> #Character
BEGIN
SET #Input = #Input + #Character
END
WHILE CHARINDEX(#Character, #Input) > 0
BEGIN
SET #EndIndex = CHARINDEX(#Character, #Input)
INSERT INTO #Output(Item)
SELECT SUBSTRING(#Input, #StartIndex, #EndIndex - 1)
SET #Input = SUBSTRING(#Input, #EndIndex + 1, LEN(#Input))
END
RETURN
END
GO
Once the Function is in place the below code can be used to achieve the desired result
;WITH cte_OriginalTable(url) as
(
SELECT 'ht,ha,hb,ha|hc|hy' UNION ALL
SELECT 'ht,hb,hb|hb|hx|hx' UNION ALL
SELECT 'hz,hy,hx,hm|hm,hy' UNION ALL
SELECT 'hz,hy,hx,hm|hm,hy'
)
,cte_SaperaterFix AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS ID, replace(url, ',h', '|h') AS url
FROM cte_OriginalTable
)
,cte_Split as
(
SELECT o.*,
y.Item
FROM cte_SaperaterFix o
CROSS APPLY dbo.ufn_SplitString(o.url, '|') y
)
,cte_TotalCount AS
(
SELECT ID,COUNT(ID) AS counttotal_urls, COUNT(DISTINCT Item) AS Unique_urls, COUNT(ID) - COUNT(DISTINCT Item) AS countduplicate_urls
FROM cte_Split
GROUP BY ID
)
SELECT DISTINCT b.ID, b.url AS URLs, a.CountTotal_URLs, a.CountDuplicate_URLS, STUFF(( SELECT DISTINCT '|' + b1.Item AS [text()]
FROM cte_Split b1
WHERE
b.ID = b1.ID
FOR XML PATH('')
), 1, 1, '' ) AS Unique_URLs, a.Unique_URLs AS CountUnique_URLs
FROM cte_TotalCount a
JOIN cte_Split b
ON a.ID = b.ID