SSIS: Using CASE Statement Within A Derived Column Transformation Expression

Question

The following is my Data Flow:
Ole DB Source > Copy Column > Derived Column >Ole DB Command
My OLE DB Source has the following SQL command task:
SELECT *
FROM Repair R
LEFT OUTER JOIN Vehicle V
ON R.SN = V.SN
AND R.Reg = V.Reg
LEFT OUTER JOIN Product P
ON R.PID = P.PID
This yields a column of concern for me named PartNumber, which are represented by the following 2 formats:
The following are my Copied Columns:
Input Column = PartNumber
Output Alias = Copy of PartNumber
The following are my Derived Column expressions:
Derived Column Name Derived Column Expression
Name Replace 'PartNumber' LEFT(PartNumber,FINDSTRING(PartNumber,"-",1) - 1)
Copy of Name Replace 'Copy of PartNumber' RIGHT([Copy of PartNumber],LEN([Copy of PartNumber]) - FINDSTRING([Copy of PartNumber],"-",1))
So My PartNumber Column is Replaced with ######### of type
string and the Copy of PartNumber column is replaced with
#### of type int
As I stated earlier PartNumber also is in the format of %-%-% which raises the following question:
How can I replace PartNumber Column with NULL if in format of
%-%-% and take the PartNumber and put it in new column named
SubPart while keeping all the logic within SSIS objects?
So in essence I want to do something like the following:
PartNumber = CASE
WHEN 'PartNumber' LIKE '%-%-%'
THEN ABC = PartNumber AND PartNumber IS NULL
END
I have tried the case statement in a Derived Column expression and is not working. Would I add the
CASE statement to the SQL command task in my OLE DB Source?
I hope this question is concise for you.

Answer 1

If it must be in SSIS, I would put a derived column stage earlier in the process to do my check for me. Then in the second derived column stage do the check against each output column (part, subpart, copy of part) to decide which way it goes
PS Not sure if it's a 2012 function but SSIS has a function called TOKEN that will allow you to pull your subparts for you rather than the left/right you are doing