need help with parsing string

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need help with parsing string

is250sp

SSCarpal Tunnel

Points: 4361
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January 8, 2010 at 3:46 pm

#136531

I have a script that finds the 2nd period and returns the first and second nodes in a string. It works fine as long as there is a second period, however, we've added more data without the second period and the script is no longer valid.

script:

select substring(@variable, 1, charindex('.', @variable) + 1 + charindex('.', substring(@variable, charindex('.', @variable) + 1, 100)) - 2

@variable values and desired return result:

Node1.Node2.Node3 would return Node1.Node2

Node1.Node2.Node3.Node4 would return Node1.Node2

Node1.Node2 would return Node1.Node2 (with the script above, this returns just Node1)

Viewing 5 posts - 1 through 4 (of 4 total)

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John Rowan SSC Guru Points: 56440 More actions · Answer 1

It looks to me like you need a split function that works with a tally table. You shouldn't have to re-code your function every time the data chages.

You should be able to find several versions of a TSQL based split function here on SSC if you search. I'd recommend looking for one that used a numbers/tally table.

John Rowan

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Lowell SSC Guru Points: 323482 More actions · Answer 2

just use a case statement to check for the number of periods; if it's two or more, use your formula, else get the full string.

typical results:



Node1.Node2

Node1.Node2

Node1.Node2

ServerName.DatabaseName

192.168

Bob

code example:



select

CASE

  WHEN (LEN(val) - len(replace(val,'.',''))) >= 2

  THEN  substring(val, 1, charindex('.', val) + 1 + charindex('.', substring(val, charindex('.', val) + 1, 100)) - 2)

  ELSE VAL

END

from (

select 'Node1.Node2.Node3' as val union all

select 'Node1.Node2.Node3.Node4' union all

select 'Node1.Node2' union all

select 'ServerName.DatabaseName.SchemaName.objectName' union all

select '192.168.1.100' union all

select 'Bob' ) x

Lowell

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ChrisM@home SSC-Insane Points: 24260 More actions · Answer 3

is250sp (1/8/2010)

I have a script that finds the 2nd period and returns the first and second nodes in a string. It works fine as long as there is a second period, however, we've added more data without the second period and the script is no longer valid.

script:

select substring(@variable, 1, charindex('.', @variable) + 1 + charindex('.', substring(@variable, charindex('.', @variable) + 1, 100)) - 2

@variable values and desired return result:

Node1.Node2.Node3 would return Node1.Node2

Node1.Node2.Node3.Node4 would return Node1.Node2

Node1.Node2 would return Node1.Node2 (with the script above, this returns just Node1)

If the maximum number of nodes is 4, then you could use parsename()

SELECT PARSENAME (val, 1), PARSENAME (val, 2), PARSENAME (val, 3), PARSENAME (val, 4)



from (

	select 'Node1.Node2.Node3' as val union all

	select 'Node1.Node2.Node3.Node4' union all

	select 'Node1.Node2' union all

	select 'ServerName.DatabaseName.SchemaName.objectName' union all

	select '192.168.1.100' union all

select 'Bob' ) x

Results:

(Col1) (Col2) (Col3) (Col4)



Node3		Node2		Node1		NULL

Node4		Node3		Node2		Node1

Node2		Node1		NULL		NULL

objectName	SchemaName	DatabaseName	ServerName

100		1		168		192

Bob NULL NULL NULL

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Hidden RBAR: Triangular Joins[/url] / The "Numbers" or "Tally" Table: What it is and how it replaces a loop[/url] Jeff Moden[/url]

Paul White SSC Guru Points: 150457 More actions · Answer 4

A quick-and-dirty solution is to just add an extra period to each string during processing. Your script then runs without modification:



DECLARE @Data TABLE (data VARCHAR(50) NOT NULL);

INSERT @Data (data) VALUES ('N1.N2.N3.N4'), ('N1.N2.N3'), ('N1.N2'), ('N1');

WITH    D (data) AS (SELECT data + '.' FROM @Data)

SELECT  SUBSTRING(data, 1, CHARINDEX('.', data) + 1 + CHARINDEX('.', SUBSTRING(data, CHARINDEX('.', data) + 1, 100)) - 2)

FROM    D;

Paul White
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