How can I separate dynamic data (different lengths) with a substring? - sql

Question

I need some assistance on separating data based on dynamic ranges with a start and end point.
For example, a string that looks like this:
N=Chris,,Lane,,M,,
N=Alen,,Smith,,E,,
N= is static and always the same. I can start a substring after the equals. The name on the other hand is dynamic and always changing in length, BUT there is a terminator with the commas. How do I select each segment of this column with SQL where Chris, Lane and M can be displayed in separate columns for First, Last and Middle name?

Answer 1

Adapting this example
SELECT p.id, REPLACE(p.[1], 'N=', '') Col1, p.[2] Col2, p.[3] Col3, p.[4] Col4, p.[5] Col5, p.[6] Col6, p.[7] Col7
FROM (
SELECT id, substring(d, start + 2, endPos - Start - 2) token, row_number() OVER (
PARTITION BY id ORDER BY start
) n
FROM (
SELECT id, d, n start, charindex(',', d, n + 2) endPos
FROM num
CROSS JOIN (
SELECT id, ',' + d + ',' d
FROM #m
) m
WHERE n < len(d) - 1
AND substring(d, n + 1, 1) = ','
) d
) pvt
Pivot(max(token) FOR n IN ([1], [2], [3], [4], [5], [6], [7])) p
demo

Answer 2

It's not pretty, but you can do parsing like this with charindex and locate:
select
substring(text, 3, charindex(',', text) - 3) firstName,
substring(text, charindex(',', text, charindex(',', text) + 1) + 1, charindex(',', text, charindex(',', text, charindex(',', text) + 1) + 1) - charindex(',', text, charindex(',', text) + 1) - 1) lastName,
substring(text, charindex(',', text, charindex(',', text, charindex(',', text, charindex(',', text) + 1) + 1) + 1) + 1, charindex(',', text, charindex(',', text, charindex(',', text, charindex(',', text, charindex(',', text) + 1) + 1) + 1) + 1) - charindex(',', text, charindex(',', text, charindex(',', text, charindex(',', text) + 1) + 1) + 1) - 1) middleName,
from
t
SQLFiddle here

Answer 3

Sounds like a job for.... split function!!! fn_split()
http://technet.microsoft.com/en-us/library/aa496058(v=sql.80).aspx
CREATE FUNCTION dbo.fn_Split(#text varchar(8000), #delimiter varchar(20) = ' ')
RETURNS #Strings TABLE
(
position int IDENTITY PRIMARY KEY,
value varchar(8000)
)
AS
BEGIN
DECLARE #index int
SET #index = -1
WHILE (LEN(#text) > 0)
BEGIN
SET #index = CHARINDEX(#delimiter , #text)
IF (#index = 0) AND (LEN(#text) > 0)
BEGIN
INSERT INTO #Strings VALUES (#text)
BREAK
END
IF (#index >= 1)
BEGIN
INSERT INTO #Strings VALUES (LEFT(#text, #index - 1))
SET #text = RIGHT(#text, (LEN(#text) - #index))
END
ELSE
SET #text = RIGHT(#text, (LEN(#text) - #index))
END
RETURN
END
GO
SELECT * FROM dbo.fn_Split('N=Chris,,,,,Lane,,M,,',',')
or you can pivot to your liking....
SELECT [1] AS FirstName,[2],[3] AS LastName,[4],[5] AS MiddleInitial,[6]
FROM (
SELECT POSITION, VALUE
FROM dbo.fn_Split('N=Chris,,Lane,,M,,',',')
) p
PIVOT (MAX(VALUE) FOR POSITION IN ([1],[2],[3],[4],[5],[6])) AS pvt
Didn't want to do all the work but the downvote upset me... I don't know why it feel so personal when I'm downvoted.... I need to work on that. =(