We help IT Professionals succeed at work.

section a string

134 Views
Last Modified: 2017-05-04
I am creating a function in sql to parse a sting it to a variable number of sections base on a delimiter that is set by a parameter.
Below is the function.

ALTER FUNCTION [dbo].[L_SPLIT]
(
      @P1 varchar(max), -- string to parse
      @P2 int,      -- number of sections
      @P3 varchar(10),-- Delimiter
    @P4 int –- section to return
)
RETURNS varchar(max)
AS
BEGIN
      -- Declare the return variable here
      
Declare @products varchar(Max)
DECLARE  @cleanInput varchar(max)
Declare @TEST VARCHAR(10)
Declare @I int
set @I =1
SET @TEST = '%'+ @P3+'%'
set @products = @P1

--WHILE LEN(@products) > 0

 WHILE  @I <= @P4 and  @I <= @P2

    BEGIN
        SET @cleanInput = SUBSTRING(@products,
                                    0,
                                    PATINDEX(@TEST, @products))

        SET @products = SUBSTRING(@products,
                                  LEN(@cleanInput + @P2) + 1,
                                  LEN(@products))
   set @I = @I + 1
 END
 set @cleanInput = CASE
                WHEN @P4 < @P2 THEN @cleanInput
                Else  @products  
               end
      -- Return the result of the function
      RETURN @cleanInput
END


When I Run
select
          dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',1)

it returns  1  which is correct

when I run
        select
          dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',2)
it returns  NULL and it should be 20

when I run select
          dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',3)
It returns  |3|343|44|6|8765  it should be 3|343|44|6|8765
Comment
Watch Question

HainKurtSr. System Analyst
CERTIFIED EXPERT

Commented:
i could not get the logic

select dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',1)
it returns  1  which is correct

select dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',2)
it returns  NULL and it should be 20 

select dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',3)
It returns  |3|343|44|6|8765  it should be 3|343|44|6|8765

Open in new window

Author

Commented:
I am trying to break a string into a number of sections base on a delimiter and return the section of my choice
HainKurtSr. System Analyst
CERTIFIED EXPERT

Commented:
ok but the examples you gave does not make sense to me...

for example this
select dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',3)
It returns  |3|343|44|6|8765  it should be 3|343|44|6|8765

Open in new window

Co-Founder and Chief Architect
CERTIFIED EXPERT
Top Expert 2016
Commented:
This problem has been solved!
(Unlock this solution with a 7-day Free Trial)
UNLOCK SOLUTION
Sharath SData Engineer
CERTIFIED EXPERT

Commented:
<<
when I run select
          dbo.L_SPLIT('1|20|3|343|44|6|8765',3,'|',3)
It returns  |3|343|44|6|8765  it should be 3|343|44|6|8765 >>
Why it should return 3|343|44|6|8765 and why not just 3?

What is the purpose of 2nd parameter (i.e. sections) in your string?

This function splits the string on the passed delimiter and returns the value at desired location.
CREATE FUNCTION splitString
(@p1 varchar(max),
 @p2 varchar(1),
 @p3 int
)
RETURNS VARCHAR(100) AS 
BEGIN

 DECLARE @string VARCHAR(100)
 
;WITH ToXml AS
    (
        SELECT  CAST(('<td><![CDATA[' + REPLACE(@p1, @p2, ']]></td><td><![CDATA[') + ']]></td>') AS XML) AS XmlData
    ),
   CTE AS (
    SELECT  td.value('.', 'NVARCHAR(255)') AS [value],
            ROW_NUMBER() OVER (ORDER BY (SELECT 1)) rn
    FROM    ToXml
        CROSS APPLY XmlData.nodes('td') A ( td ))
 SELECT @string = value FROM CTE WHERE rn = @p3
 RETURN @string
 END
 GO
 
 SELECT dbo.splitString('1|20|3|343|44|6|8765','|',1); --1
 SELECT dbo.splitString('1|20|3|343|44|6|8765','|',2); --20
 SELECT dbo.splitString('1|20|3|343|44|6|8765','|',3); --3

Open in new window

Gain unlimited access to on-demand training courses with an Experts Exchange subscription.

Get Access
Why Experts Exchange?

Experts Exchange always has the answer, or at the least points me in the correct direction! It is like having another employee that is extremely experienced.

Jim Murphy
Programmer at Smart IT Solutions

When asked, what has been your best career decision?

Deciding to stick with EE.

Mohamed Asif
Technical Department Head

Being involved with EE helped me to grow personally and professionally.

Carl Webster
CTP, Sr Infrastructure Consultant
Empower Your Career
Did You Know?

We've partnered with two important charities to provide clean water and computer science education to those who need it most. READ MORE

Ask ANY Question

Connect with Certified Experts to gain insight and support on specific technology challenges including:

  • Troubleshooting
  • Research
  • Professional Opinions