Merging 2 DSO data to another DSO

Question

Have a query w.r.to merge of DSO data.
DSO 1
100    10    ABC  24.5
100    20    DEF  35.6
DSO 2
100   10  1001  56.8
100   10  1002  58.9
Now, in DSO 1, 100, 10 are header and item which are keys
In DSO 2, 1001, 1002 are document no so 3 keys. However this data might get updated later than DSO 1 as part of delta. Below is final output req
DSO 3 -  same keys as DSO 2. Planning to do delta dtp from both these dsos to DSO 3 without any ABAP.
100   10  1001  ABC  24.5  56.8
100   20     -      DEF  35.6    - 
100   10  1002  ABC  24.5  58.9
Now if there is a new record for 20 in DSO 2, will it update the 2nd record or will it create a new record as below? I think this should overwrite 2nd record in DSO 3 and not like below. Please confirm
100   10  1001  ABC  24.5  56.8
100   20     -      DEF  35.6    -  
100   10  1002  ABC  24.5  58.9
100   20  1002  DEF  35.6  65.7

Answer 1

Sorry for the confusion....I got the below output in DSO3:
100    10     -       ABC   24.5      -
100    20     -       DEF   35.6      -
101    10     -       LMN   67.2      -
100   10  1001     -          -        56.8
100   10  1002     -          -        58.9
Now my requirement is to only show the header and item data that has document no. If there is no document no, then show the header and item data with blank document no.
Eg:  Output should be as below:
100   10  1001     ABC    24.5      56.8
100   10  1002     ABC    24.5      58.9
100   20      -         DEF    35.6        -
101   10      -         LMN    67.2       -
Now if there is a new document no for 3rd record above in next delta with doc no 1003, final o/p needs to be as below. The previous record need not be shown...
100   10  1001     ABC    24.5      56.8
100   10  1002     ABC    24.5      58.9
100   20  1003     DEF    35.6       88.5
101   10      -         LMN    67.2       -
This seems to be through ABAP. Can some one suggest and help?