Extracting a string in between two characters in sql

Question

I am having trouble extracting a selection of characters from a string

Here is a snippet of values from a field called 'TXT':

• FNP, 10/09/2018,PO-00123456 - F333330- FA_002056
• FNP, 18-09-2018,PO-00987654 - F010122- FA_002056
• FNP, 28/12/2017,PO-00123987 - F10101
• FNP, 13-03-2019,FRPO-35412 - F27272-ANNUL PO

And I wish to extract the F333330, F010122, F10101 and F27272

I have experimented with charindex, left/right, and substring but havent been able to crack it

SELECT TXT , 
CASE WHEN CHARINDEX('-',(SUBSTRING(txt,CHARINDEX('-',txt,2)+1,99)))=0
THEN 
LTRIM(RTRIM(SUBSTRING(txt,CHARINDEX('-',txt,2)+1,99)))
ELSE 
LTRIM(RTRIM(SUBSTRING(txt,CHARINDEX('-',txt,2) +1,CHARINDEX('-',SUBSTRING(txt,CHARINDEX('-',txt,2)+1,99))-1)))
END
FROM #test

My desired row set is to just show:

• F333330
• F010122
• F10101
• F27272

I have tried other variations of substring without a case statement but had no luck. Can anyone help?

Thanks, Nuems

Answer 1

Try this?

DECLARE @test TABLE (TXT VARCHAR(500));
INSERT INTO @test SELECT 'FNP, 10/09/2018,PO-00123456 - F333330- FA_002056' UNION ALL
SELECT 'FNP, 18-09-2018,PO-00987654 - F010122- FA_002056' UNION ALL
SELECT 'FNP, 28/12/2017,PO-00123987 - F10101' UNION ALL 
SELECT 'FNP, 13-03-2019,FRPO-35412 - F27272-ANNUL PO';
SELECT SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, CASE WHEN CHARINDEX('-', SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99)) = 0 THEN 99 ELSE CHARINDEX('-', SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99)) - 1 END)
FROM @test;

...or, with that one extra row:

DECLARE @test TABLE (TXT VARCHAR(500));
INSERT INTO @test SELECT 'FNP, 10/09/2018,PO-00123456 - F333330- FA_002056' UNION ALL
SELECT 'FNP, 18-09-2018,PO-00987654 - F010122- FA_002056' UNION ALL
SELECT 'FNP, 28/12/2017,PO-00123987 - F10101' UNION ALL 
SELECT 'FNP, 13-03-2019,FRPO-35412 - F27272-ANNUL PO' UNION ALL
SELECT 'FNP, 11/10/2017,PO-00112311 - F32121 regul po 112311';
SELECT SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 
    CASE 
        WHEN CHARINDEX('-', SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99)) != 0 THEN CHARINDEX('-', SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99)) - 1 
        WHEN CHARINDEX(' ', SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99)) != 0 THEN CHARINDEX(' ', SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99)) - 1 
        ELSE 99
    END)
FROM @test;

...or bonus with less repetition (uses a CTE):

WITH x AS (
    SELECT SUBSTRING(TXT, PATINDEX('%- F%', TXT) + 2, 99) AS TXT FROM @test)
SELECT SUBSTRING(TXT, 0, 
    CASE 
        WHEN CHARINDEX('-', TXT) != 0 THEN CHARINDEX('-', TXT) - 1
        WHEN CHARINDEX(' ', TXT) != 0 THEN CHARINDEX(' ', TXT) - 1
        ELSE 99
    END)
FROM x;