How to insert a hyphen between blocks of alpha and numeric characters - sql

Question

I need to insert hyphens between blocks of alpha and numeric text in a string.
I am not even sure how to start on this problem.
ABC123 -> ABC-123
ABC123XYZ -> ABC-123-XYZ
D123 -> D-123
123C -> 123-C

Answer 1

This one will work for you with single value.
DECLARE #CODE VARCHAR(50) = '12ABC123XYZ'
,#NEWCODE VARCHAR(100) = ''
;WITH CTE
AS (
SELECT NUMBER
,SUBSTRING(#CODE, NUMBER, 1) AS VAL
FROM master.dbo.spt_values
WHERE TYPE = 'P'
AND number BETWEEN 1
AND LEN(#CODE)
)
SELECT #NEWCODE = #NEWCODE + CASE
WHEN ISNUMERIC(C1.VAL) <> ISNUMERIC(ISNULL(C2.VAL, C1.VAL))
THEN '-' + C1.VAL
ELSE C1.VAL
END
FROM CTE C1
LEFT JOIN CTE C2 ON C1.number = C2.number + 1
SELECT #NEWCODE
Result : 12-ABC-123-XYZ
And If you want this to work with table column, you need to create a scalar function.
CREATE FUNCTION CODE_SPLIT
(
#CODE VARCHAR(50)
)
RETURNS VARCHAR(100)
AS
BEGIN
DECLARE #NEWCODE VARCHAR(100) ='';
;WITH CTE
AS (
SELECT NUMBER
,SUBSTRING(#CODE, NUMBER, 1) AS VAL
FROM master.dbo.spt_values
WHERE TYPE = 'P'
AND number BETWEEN 1
AND LEN(#CODE)
)
SELECT #NEWCODE = #NEWCODE + CASE
WHEN ISNUMERIC(C1.VAL) <> ISNUMERIC(ISNULL(C2.VAL, C1.VAL))
THEN '-' + C1.VAL
ELSE C1.VAL
END
FROM CTE C1
LEFT JOIN CTE C2 ON C1.number = C2.number + 1
RETURN #NEWCODE
END
GO
And call it on your actual table
Schema:
SELECT * INTO #TAB FROM(
SELECT 'ABC123' AS CODE
UNION ALL
SELECT 'ABC123XYZ'
UNION ALL
SELECT 'D123'
UNION ALL
SELECT '123C'
)A
SELECT CODE, dbo.CODE_SPLIT(CODE) AS NEWCODE FROM #TAB
Result:
+-----------+-------------+
| CODE | NEWCODE |
+-----------+-------------+
| ABC123 | ABC-123 |
| ABC123XYZ | ABC-123-XYZ |
| D123 | D-123 |
| 123C | 123-C |
+-----------+-------------+

Answer 2

patindex('%[0-9]%') return index of first number.
patindex('%[^0-9]%') return index of first non-numeric character.
You could use recursive CTE and PATINDEX like this.
DECLARE #SampleData AS TABLE
(
TextValue varchar(100)
)
INSERT INTO #SampleData
VALUES ('ABC124'), ('ABC123XYZ'), ('123C'), ('ABC'), ('1A2B3C')
;WITH cte AS
(
SELECT sd.TextValue AS RootText,
sd.TextValue AS CurrentText,
CAST('' AS varchar(100)) AS Result
FROM #SampleData sd
UNION ALL
SELECT
c.RootText,
CASE
WHEN patindex('%[0-9]%', c.CurrentText) = 0 OR patindex('%[^0-9]%', c.CurrentText) = 0
THEN ''
WHEN patindex('%[0-9]%', c.CurrentText) > patindex('%[^0-9]%', c.CurrentText)
THEN RIGHT(c.CurrentText, len(c.CurrentText) - patindex('%[0-9]%', c.CurrentText) + 1)
ELSE RIGHT(c.CurrentText, len(c.CurrentText) - patindex('%[^0-9]%', c.CurrentText) + 1)
END AS CurrentText,
CAST(
CASE
WHEN patindex('%[0-9]%', c.CurrentText) = 0 OR patindex('%[^0-9]%', c.CurrentText) = 0
THEN Result + '-' + c.CurrentText
WHEN patindex('%[0-9]%', c.CurrentText) > patindex('%[^0-9]%', c.CurrentText)
THEN Result + '-' + LEFT(CurrentText, patindex('%[0-9]%', c.CurrentText) - 1)
ELSE Result + '-' + LEFT(CurrentText, patindex('%[^0-9]%', c.CurrentText) - 1)
END AS varchar(100)
) AS Result
FROM cte c
WHERE LEN(CurrentText) > 0
)
SELECT cte.RootText, STUFF(cte.Result, 1,1,'') AS Result FROM cte
WHERE cte.CurrentText = ''
Demo link: http://rextester.com/FTYA72053