PLSQL Conditional compilation

Hi all,

I would like to do the following using conditional compiling, when the db release_name is greater than 12.2.0 then a certain operation has to be performed, else not.
When i use the below code, it always goes to the ELSE part of the IF condition.

BEGIN
    --get the current oracle release version
    SELECT release_name INTO ver_cust FROM fnd_product_groups;

    --convert customer oracle version to number
    num_version_c := to_number(REPLACE(ver_cust,'.',''));
FOR indx IN 1..abc_TBL.COUNT LOOP
          abc(indx).ADJUSTMENT_ID           := abc_TBL(indx).P_ADJUSTMENT_ID ;
          abc(indx).PHYSICAL_INVENTORY_ID   := abc_TBL(indx).P_PHYSICAL_INVENTORY_ID ;