How to get substring in SQL Server? - sql-server

Question

I have the next table, how can I get substring before and after dot(.) special character?
MyTable
------------------------------
Id Description
------------------------------
1 [Hugo].[date].[Subtotal]
2 [Juan].[date].[Subtotal]
3 [7/23/2013].[SubTotal]
4 [7/25/2013].[Total]
I am looking for the following result
MyResultTable
------------------------
MyTableId Description depth
-----------------------
1 [Hugo] 1
1 [date] 2
1 [Subtotal] 3
2 [Juan] 1
2 [date] 2
2 [Subtotal] 3
3 [7/23/2013] 1
3 [SubTotal] 2
4 [7/25/2013] 1
4 [Total] 2
I want to separate the words after a dot(.) and list the words as the following table
How can I solve it?

Answer 1

You will want to split the data based on the .. You can use a recursive CTE to split the data and return the depth:
;with cte (id, DescriptionItem, Description, depth) as
(
select id,
cast(left(Description, charindex('.',Description+'.')-1) as varchar(50)) DescriptionItem,
stuff(Description, 1, charindex('.',Description+'.'), '') Description,
1 as depth
from MyTable
union all
select id,
cast(left(Description, charindex('.',Description+'.')-1) as varchar(50)) DescriptionItem,
stuff(Description, 1, charindex('.',Description+'.'), '') Description,
depth+1
from cte
where Description > ''
)
select id, DescriptionItem, depth
from cte
order by id, depth;
See SQL Fiddle with Demo
Or you can use a UDF function that splits the data:
create FUNCTION [dbo].[Split](#String varchar(MAX), #Delimiter char(1))
returns #temptable TABLE (items varchar(MAX), depth int)
as
begin
declare #idx int
declare #slice varchar(8000)
declare #depth int = 1
select #idx = 1
if len(#String)<1 or #String is null return
while #idx!= 0
begin
set #idx = charindex(#Delimiter,#String)
if #idx!=0
set #slice = left(#String,#idx - 1)
else
set #slice = #String
if(len(#slice)>0)
insert into #temptable(Items, depth) values(#slice, #depth)
set #String = right(#String,len(#String) - #idx)
set #depth = #depth +1
if len(#String) = 0 break
end
return
end;
Then when you call the function, you will use CROSS APPLY similar to this:
select t.id, c.items description,
c.depth
from mytable t
cross apply dbo.split(t.description, '.') c
order by t.id, c.depth;
See SQL Fiddle with Demo

Answer 2

USE tempdb;
GO
IF OBJECT_ID('dbo.csv_split','U') IS NOT NULL DROP TABLE dbo.csv_split;
CREATE TABLE dbo.csv_split
(
Id INT NOT NULL PRIMARY KEY
,Description VARCHAR(100)
)
INSERT INTO dbo.csv_split(Id,Description)
VALUES
(1,'[Hugo].[date].[Subtotal]')
,(2,'[Juan].[date].[Subtotal]')
,(3,'[7/23/2013].[SubTotal]')
,(4,'[7/25/2013].[Total]');
WITH cte_xml AS
(
Select csv.Id
,CONVERT(XML,'<desc>'
+ REPLACE(csv.Description,'.','</desc><desc>')
+ '</desc>') AS xml_desc
From dbo.csv_split csv
)
,cte_shred_xml AS
(
Select t.Id
,xml_desc_nodes.value('(.)','varchar(50)') AS Description
,ROW_NUMBER() OVER(PARTITION BY t.Id ORDER BY t.Id ) AS Depth
From cte_xml t
CROSS APPLY t.xml_desc.nodes('/desc') AS t2(xml_desc_nodes)
)
Select *
From cte_shred_xml

Answer 3

Here is a simple example. I created your table as #test and used both a cursor and a loop within the cursor.
DECLARE #test TABLE ( id INT, NAME VARCHAR(MAX) )
INSERT #test
VALUES ( 1, '[Hugo].[date].[Subtotal]' )
INSERT #test
VALUES ( 2, '[Juan].[date].[Subtotal]' )
INSERT #test
VALUES ( 3, '[7/23/2013].[SubTotal]' )
INSERT #test
VALUES ( 4, '[7/25/2013].[Total]' )
DECLARE #id INT ,
#name VARCHAR(MAX)
DECLARE #values TABLE
(
MyTableId INT ,
Description VARCHAR(MAX) ,
Depth INT
)
DECLARE #v VARCHAR(2000) ,
#i INT ,
#depth INT
DECLARE #MyTableList CURSOR
SET
#MyTableList = CURSOR FOR SELECT id, name FROM #test
OPEN #MyTableList
FETCH NEXT FROM #MyTableList INTO #id, #name
WHILE ##FETCH_STATUS = 0
BEGIN
SET #depth = 1
SET #i = PATINDEX('%.%', #name)
WHILE #i > 0
BEGIN
INSERT #values
VALUES ( #id, SUBSTRING(#name, 1, #i - 1), #depth )
SET #name = SUBSTRING(#name, #i + 1, LEN(#name) - #i)
SET #i = PATINDEX('%.%', #name)
SET #depth = #depth + 1
END
INSERT #values
VALUES ( #id, #name, #depth )
FETCH NEXT FROM #MyTableList INTO #id, #name
END
SELECT MyTableId ,
Description ,
Depth
FROM #values
You output should look like this.
MyTableId Description Depth
1 [Hugo] 1
1 [date] 2
1 [Subtotal] 3
2 [Juan] 1
2 [date] 2
2 [Subtotal] 3
3 [7/23/2013] 1
3 [SubTotal] 2
4 [7/25/2013] 1
4 [Total] 2