Mline UDF - Return specific line

Submitted by Sergey on November 23, 2007 - 05:00 UTC
topic: 
sql
tsql
udf
mssql
code

The ufn_Mlines() UDF for SQL Server is similar to the VFP Mline() function but w/o third parameter.
It's more an example than finished UDF. I didn't do much testing on it.

$SAMPLECODE$





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-- ufn_Mline ---
IF EXISTS (SELECT * FROM   sysobjects WHERE  name = N'ufn_Mline')
    DROP FUNCTION ufn_Mline
GO
CREATE FUNCTION ufn_Mline 
	(	@Str varchar(8000),
		@LineNumber int)
RETURNS varchar(8000)
AS
/* Returns a specific line from a string. Each line is separated by @separator 

 Parameters:
    @str  - string passed in
    @LineNumber - Line number to return
 Returns either a line requested or empty string if @LineNumber exceeds # of lines in @str
*/
BEGIN
	DECLARE @separator varchar(16), @Line varchar(8000), @pos int, @i int
	-- Lines are separated by CR (carrage return) only
	SET @separator = CHAR(13)
	SET @Line = ''
	SET @i = 1
	WHILE DATALENGTH(@str) > 0 BEGIN
		SET @pos = CHARINDEX(@separator, @str)
		IF @pos = 0 
			SET @pos = DATALENGTH(@str)+1
		IF @i = @LineNumber BEGIN							
			SET @Line = LEFT(@str, @pos -1)
			BREAK
		END	
		SET @str = SUBSTRING(@str, @pos + DATALENGTH(@separator), 8000)
		SET @i = @i + 1
	END
	
	RETURN @Line

END

GO

-- Sample of using ufn_Mline UDF
SELECT dbo.ufn_Mline('The quick brown fox' + CHAR(13) + 'jumps over the lazy dog',1)
SELECT dbo.ufn_Mline('The quick brown fox' + CHAR(13) + 'jumps over the lazy dog',2)
SELECT dbo.ufn_Mline('The quick brown fox' + CHAR(13) + 'jumps over the lazy dog',3)

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