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  1. Rules Repository
  2. RSPEC-1862 Related "if/else if" statements should not have the same condition
  3. RSPEC-1868

PL/SQL: Related "IF/ELSIF" statements and "WHEN" clauses in a "CASE" should not have the same condition

    Details

    • Type: Language-Specification
    • Status: Active
    • Resolution: Unresolved
    • Labels:
      None
    • Impact:
      Unknown 'null' severity
    • Likelihood:
      Unknown 'null' severity

      Description

      A CASE and a chain of IF/ELSIF statements is evaluated from top to bottom. At most, only one branch will be executed: the first one with a condition that evaluates to true.

      Therefore, duplicating a condition automatically leads to dead code. Usually, this is due to a copy/paste error. At best, it's simply dead code and at worst, it's a bug that is likely to induce further bugs as the code is maintained, and obviously it could lead to unexpected behavior.

      Noncompliant Code Example

      IF param == 1 THEN
        x := 'A';
      ELSIF param == 2 THEN
        x := 'B';
      ELSIF param == 1 THEN -- Noncompliant, for sure this is a bug
        x := 'C';
      END IF;
      
      result := CASE param
         WHEN 1 THEN 'A'
         WHEN 2 THEN 'B'
         WHEN 1 THEN 'C'  -- Noncompliant
         ELSE 'D'
      END;
      

      Compliant Solution

      IF param == 1 THEN
        result := 'A';
      ELSIF param == 2 THEN
        result := 'B';
      ELSIF param == 3 THEN
        result := 'C';
      END IF;
      
      result := CASE param
         WHEN 1 THEN 'A'
         WHEN 2 THEN 'B'
         WHEN 3 THEN 'C'
         ELSE 'D'
      END;
      

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            • Assignee:
              Unassigned
              Reporter:
              freddy.mallet Freddy Mallet (Inactive)
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              Dates

              • Created:
                Updated: