title: How to test if a string is inside a list of predefined strings?
body: <p>I defined a list of strings, which contains different country codes (like <code>USA,CHINA,HK,JPN</code>, etc.).</p>
  <p>How can I check, if an input variable is the country code in the list?</p>
  <p>I use the following code to test, but it fails.</p>
  <pre><code>declare
   country_list  CONSTANT VARCHAR2(200) := USA,CHINA,HK,JPN;
   input VARCHAR2(200);
  begin
   input  := 'JPN';
   IF input   IN  (country_list)
           DBMS_OUTPUT.PUT_LINE('It is Inside');
      else       
           DBMS_OUTPUT.PUT_LINE('It is not  Inside');
   END IF;
  end;
  </code></pre>