title: Oracle query for getting list of countries
body: <p>I am using the oracle 10g and i have table with column names firstname , lastname , country and region .</p>
  
  <pre><code>country | region
  --------|----------
  India   | Asia
  China   | Asia
  Ireland | Europe
  England | Europe
  </code></pre>
  
  <p>Below are the senarios,</p>
  
  <ol>
  <li><p>when we pass "ALL" for country and region , output query should be</p>
  
  <pre><code>select * from Test_Table
  </code></pre></li>
  <li><p>when we pass "India,China" for counrty and "Asia , Europe" for region , output query should be</p>
  
  <pre><code>select * from Test_Table where counrty in (Malayasia,japan) and region in (Asia , Europe)
  </code></pre></li>
  </ol>
  
  <p>how do i combine this into the single query in which values are passed , Any help would be greatly appreciated.</p>