ABAP in BW Tranformations Syntax Correction

Question

Hi,
As i am beginner in ABAP please correct the Start/End routine which i have written in Transformations for the below requirement
DSO1------->DSO2
While load data to DSO1-->DSO2 in need a look that refer active table of DSO3 and perform if condition to fill value to a field in DSO2
DSO1 (SOURCE FIELDS)
Field X
Field Y (X,Y are Key fields)
Field Z
Field W
DSO2 (Result Field)
Field P (The field which i want to update with Value by routine)
DSO3 (Look up)
Field A
Field B (A,B are Key fields) (A=X,B=Y)
Field C
Requirement: While loading data from DSO1-->DSO2...We should read active table of DSO3 and pass it to Internal Table (A,B,C)with a key (A=X,B=Y) and in the end routine First check wether
if Field C is not initial...then Result Field P should be updated with E
ELSE CHECK SOURCE FIELD Field Z = 1..then Result Field P should be updated with F
ELSE CHECK SOURCE FIELD Field W = T..then Result Field P should be updated with G
else if all the above conditions are not met .then Result Field P should be updated with H
Syntax i wrote (Not working correctly)
Declaration-Global
TYPES: BEGIN OF ty_sou,
W TYPE /bi0/W,
Z TYPE /bi0/Z, END OF ty_sou,
BEGIN OF ZDSO_3,
A TYPE /bi0/oiA,
B TYPE /bi0/oiB,
C TYPE /bi0/oiC, END OF ZDSO_3.
DATA : ty_ZDSO_3_wa TYPE ZDSO_3,
ty_ZDSO_3_tab TYPE TABLE OF ZDSO_3,
ty_ZDSO_3_tab_temp TYPE TABLE OF ZDSO_3.
DATA : ty_sou_tab TYPE TABLE OF ty_sou,
ty_sou_wa TYPE ty_sou.
Routine Start
LOOP AT SOURCE_PACKAGE ASSIGNING .
IF -XIS NOT INITIAL AND -Y IS NOT INITIAL.
ty_ZDSO_3_wa-A = -X.
ty_ZDSO_3_wa-B = -Y.
ty_sou_wa-Z = -Z.
ty_sou_wa-W = -W.
COLLECT ty_sou_wa INTO ty_sou_tab.
COLLECT ty_ZDSO_3_wa INTO ty_ZDSO_3_tab.
ENDIF.
ENDLOOP.
*Select Statement to select values from ZDSO_3 Active Table
SELECT A B C FROM /bic/aZDSO_300 INTO TABLE ty_ZDSO_3_tab_temp FOR ALL ENTRIES IN ty_ZDSO_3_tab WHERE
A = ty_ZDSO_3_tab-A.
SORT ty_ZDSO_3_tab BY A B.
But this is not working...i tried to debug but as i am a learner in ABAP i am not familiar.... Please advise me where or what is wrong with my code and greatful if you can make changes

Answer 1

Routine End
LOOP AT RESULT_PACKAGE ASSIGNING<RESULT-FIELD>-/ .
Read table ty_ZDSO_3_tab_temp into ty_ZDSO_3_wa
with key A = -P B = -Q binary search.
If sy-subrc = 0.
IF ty_ZDSO_3_wa-C IS NOT INITIAL.
<RESULT-FIELD>-/BIC/P = 'E'.
ELSEIF ty_sou_wa-Z = 1.
<RESULT-FIELD>-/-/BIC/P = 'Fu2019.
ELSEIF ty_sou_wa-W= 'T'.
<RESULT-FIELD>-/-/BIC/P = 'G'.
ELSE.
<RESULT-FIELD>-/-/BIC/P = 'H'.
ENDIF.
Endif.