Update Rules to deal with Asymmetrical Records

Question

Hello,
Is there a way with standard update rules one can handle the following scenario:
Incoming Datapackage:
Char  Char1   Char2
XYZ    A      -
XYZ    -      B
Desired result in an ODS (Char is the key of the ODS)
Char  Char1   Char2
XYZ   A         B
It is not known ahead of time whether char 1 or char 2 will be filled in so 2 URs is not an option.
An intermediate ODS or recursive look-ups are option but I am wondering if there is an option like:
"update only if non-blank" or is that too much to expect?

Answer 1

Why would the active table be empty? All active records will be saved to the active ODS Table...
I would code the following:
Select CHAR2 FROM ODS_TABLE WHERE CHAR = XYZ INTO TABLE
ODS_VALUE.
IF sy-subrc = 0.
DATA_PACKAGE-CHAR2 = ODS_VALUE-CHAR2.
MODIFY DATA_PACKAGE.
ENDIF.