如果不满足条件，派生列表达式SSIS如何忽略表达式？

Question

I currently have the below expressions which splits up a string of text based on a hyphen (-) so that it can be mapped to different fields using Derived column transformation in SSIS/SSDT. However I have noticed that some data does meet the criteria eg. some data does not have any hyphens or just one.

What could I add to the statement in order to ignore if condition is not met?

my current expressions are:

SUBSTRING(FIELDNAME,
FINDSTRING(FIELDNAME,"-",1) + 1,
(FINDSTRING(FIELDNAME,"-",2) - FINDSTRING(FIELDNAME,"-",1)) - 1)

and

SUBSTRING(FIELDNAME,1,FINDSTRING(FIELDNAME,"-",1) - 1)

Thanks

Answer 1

This function currently return 9 positions, but it is easy to expand or reduce.

Notice that we are appending a '-' to the string to be processed

Declare @Sample table (FIELDNAME varchar(200))
Insert Into @Sample values
('ABC-123-XYZ'),
('Some-Text'),
('NoHyphen')

Select *
 From @Sample A
 Cross Apply [dbo].[udf-Str-Parse-Row](A.FIELDNAME+'-','-') B

Returns

FIELDNAME   Pos1     Pos2       Pos3    Pos4    Pos5    Pos6    Pos7    Pos8    Pos9
ABC-123-XYZ ABC      123        XYZ     NULL    NULL    NULL    NULL    NULL
Some-Text   Some     Text       NULL    NULL    NULL    NULL    NULL    NULL
NoHyphen    NoHyphen NULL       NULL    NULL    NULL    NULL    NULL    NULL

OR with just a String

Select * from [dbo].[udf-Str-Parse-Row]('ABC-123-XYZ'+'-','-')

Returns

Pos1    Pos2    Pos3    Pos4    Pos5    Pos6    Pos7    Pos8    Pos9
ABC     123     XYZ     NULL    NULL    NULL    NULL    NULL    NULL

The UDF if needed

CREATE FUNCTION [dbo].[udf-Str-Parse-Row] (@String varchar(max),@Delimiter varchar(10))
Returns Table 
As
Return (
    Select Pos1 = xDim.value('/x[1]','varchar(max)')
          ,Pos2 = xDim.value('/x[2]','varchar(max)')
          ,Pos3 = xDim.value('/x[3]','varchar(max)')
          ,Pos4 = xDim.value('/x[4]','varchar(max)')
          ,Pos5 = xDim.value('/x[5]','varchar(max)')
          ,Pos6 = xDim.value('/x[6]','varchar(max)')
          ,Pos7 = xDim.value('/x[7]','varchar(max)')
          ,Pos8 = xDim.value('/x[8]','varchar(max)')
          ,Pos9 = xDim.value('/x[9]','varchar(max)')
     From (Select Cast('<x>' + Replace(@String,@Delimiter,'</x><x>')+'</x>' as XML) as xDim) A
)
--Select * from [dbo].[udf-Str-Parse-Row]('Dog,Cat,House,Car',',')
--Select * from [dbo].[udf-Str-Parse-Row]('John Cappelletti',' ')