title: Decode getting ORA-00938 error
body: <p>My current SQL is as below:</p>
  
  <pre><code>CASE
      WHEN PARENT.ASLNO IS NULL THEN SUBCATEGORIES.SUBCATEGORY_LIST
      -- #5098
      ELSE DECODE(ASL.CATEGORY_NAME, null,
        NVL(SUBCATEGORIES.SUBCATEGORY_LIST,
          SUBCATEGORIES_PARENT.SUBCATEGORY_LIST),
        decode(SUBCATEGORIES.SUBCATEGORY_LIST,null,null,'N/A'))
      -- End #5098
  END AS SUPSPD_SUBCATEGORY_LIST
  </code></pre>
  
  <p>I am trying to change the following sql </p>
  
  <pre><code>DECODE(ASL.CATEGORY_NAME, null,
    NVL(SUBCATEGORIES.SUBCATEGORY_LIST,
      SUBCATEGORIES_PARENT.SUBCATEGORY_LIST),
    decode(SUBCATEGORIES.SUBCATEGORY_LIST,null,null,'N/A'))
  </code></pre>
  
  <p>to </p>
  
  <pre><code>DECODE(ASL.CATEGORY_NAME, null,
    DECODE(SUBCATEGORIES.SUBCATEGORY_LIST,
      SUBCATEGORIES_PARENT.SUBCATEGORY_LIST),
    decode(SUBCATEGORIES.SUBCATEGORY_LIST,null,null,'N/A'))
  </code></pre>
  
  <p>but I am getting ORA-00938 not enough arguments for function?</p>