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G-4250: Avoid using identical conditions in different branches of the same IF or CASE statement.

Blocker

Maintainability, Reliability, Testability

Reason

Conditions are evaluated top to bottom in branches of a case statement or chain of if/elsif statements. The first condition to evaluate as true leads to that branch being executed, the rest will never execute. Having an identical duplicated condition in another branch will never be reached and will be dead code.

Example (bad)

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declare
   l_color types_up.color_code_type;
begin
   case l_color
      when constants_up.co_red then
         my_package.do_red();
      when constants_up.co_blue then
         my_package.do_blue();
      when constants_up.co_red then  -- never reached
         my_package.do_black();      -- dead code
      else
         null;
   end case;
end;
/

Example (good)

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declare
   l_color types_up.color_code_type;
begin
   case l_color
      when constants_up.co_red then
         my_package.do_red();
      when constants_up.co_blue then
         my_package.do_blue();
      when constants_up.co_black then
         my_package.do_black();
      else
         null;
   end case;
end;
/