Can we use if/else condtions like

Question

can we use if [condtion1]
then [condition2]
elseif [condtion3]
then [conditon4]
in oracle.

Answer 1

Nested Case could help you:
Select *
from
       <table_name>
where
      <col1> =
      (case when <condition_1> then
                               (case when <condition_2> then <result_2>
                                     when <condition_3> then <result_3> end)
       else <some_other_result> end);