Splitting a dynamic string

问题

I need help parsing a dynamic string(see below). This string can change to only have one set of values to two, to three(like the one below).

Raw String:

valueA=valueB=valueC=valueD==valueE&valueA=valueB=valueC=valueD==valueE&valueA=valueB=valueC=valueD==valueE

End Result: VelueB, ValueB, ValueB

I have been able to extract valueA using the STUFF and CHARINDEX function(see below) but I'm having difficulty just getting valueB. I have also tried doing it in ssrs using the split function but getting nowhere.

STUFF(( SELECT  ',' + ' ' + SUBSTRING(param, 1,
                                              CHARINDEX('=', param) - 1)
                FROM    dbo.Fn_mvparam(column_a, '&') AS fm
              FOR
                XML PATH('')
              ), 1, 1, ' ')

回答1:

This should do the trick for you. Hope its useful to you

CREATE FUNCTION uft_DoubleSplitter 
(   
    -- Add the parameters for the function here
    @String VARCHAR(4000), 
    @Splitter1 CHAR,
    @Splitter2 CHAR
)
RETURNS @Result TABLE (Id INT,MId INT,SValue VARCHAR(4000))
AS
BEGIN
DECLARE @FResult TABLE(Id INT IDENTITY(1, 1),
                   SValue VARCHAR(4000))
DECLARE @SResult TABLE(Id INT IDENTITY(1, 1),
                   MId INT,
                   SValue VARCHAR(4000))
SET @String = @String+@Splitter1

WHILE CHARINDEX(@Splitter1, @String) > 0
    BEGIN
       DECLARE @WorkingString VARCHAR(4000) = NULL

       SET @WorkingString = SUBSTRING(@String, 1, CHARINDEX(@Splitter1, @String) - 1)
       --Print @workingString

       INSERT INTO @FResult
       SELECT CASE
            WHEN @WorkingString = '' THEN NULL
            ELSE @WorkingString
            END

       SET @String = SUBSTRING(@String, LEN(@WorkingString) + 2, LEN(@String))

    END
IF ISNULL(@Splitter2, '') != ''
    BEGIN
       DECLARE @OStartLoop INT
       DECLARE @OEndLoop INT

       SELECT @OStartLoop = MIN(Id),
            @OEndLoop = MAX(Id)
       FROM @FResult

       WHILE @OStartLoop <= @OEndLoop
          BEGIN
             DECLARE @iString VARCHAR(4000)
             DECLARE @iMId INT

             SELECT @iString = SValue+@Splitter2,
                   @iMId = Id
             FROM @FResult
             WHERE Id = @OStartLoop

             WHILE CHARINDEX(@Splitter2, @iString) > 0
                BEGIN
                    DECLARE @iWorkingString VARCHAR(4000) = NULL

                    SET @IWorkingString = SUBSTRING(@iString, 1, CHARINDEX(@Splitter2, @iString) - 1)

                    INSERT INTO @SResult
                    SELECT @iMId,
                         CASE
                         WHEN @iWorkingString = '' THEN NULL
                         ELSE @iWorkingString
                         END

                    SET @iString = SUBSTRING(@iString, LEN(@iWorkingString) + 2, LEN(@iString))

                END

             SET @OStartLoop = @OStartLoop + 1
          END
       INSERT INTO @Result
       SELECT MId AS PrimarySplitID,
            ROW_NUMBER() OVER (PARTITION BY MId ORDER BY Mid, Id) AS SecondarySplitID ,
            SValue
       FROM @SResult
    END
ELSE
    BEGIN
       INSERT INTO @Result
       SELECT Id AS PrimarySplitID,
            NULL AS SecondarySplitID,
            SValue
       FROM @FResult
    END
RETURN

Usage:

--FirstSplit
SELECT * FROM uft_DoubleSplitter('ValueA=ValueB=ValueC=ValueD==ValueE&ValueA=ValueB=ValueC===ValueE&ValueA=ValueB==ValueD===','&',NULL)

--Second Split
SELECT * FROM uft_DoubleSplitter('ValueA=ValueB=ValueC=ValueD==ValueE&ValueA=ValueB=ValueC===ValueE&ValueA=ValueB==ValueD===','&','=')

Scenario Answer:

SELECT fn.SValue
FROM uft_DoubleSplitter('ValueA=ValueB=ValueC=ValueD==ValueE&ValueA=ValueB=ValueC===ValueE&ValueA=ValueB==ValueD===', '&', '=')AS fn
WHERE fn.mid = 2

回答2:

This should do it:

REPLACE(@Param, "=", ", ")

来源：https://stackoverflow.com/questions/25024198/splitting-a-dynamic-string