title: Append A Value To The Existing Value In SQL, facing error
body: <p>I have a table in which there is a column name associated_ids with datatype as varchar2(4000). It contains a value and i need to append the new value with existing value. Using below update query:</p>
  <pre><code>update ncl_getafix.service_graph 
  set Associated_ids = Associated_ids + ',' + '95d4980b-d12c-4854-97c6-bd9854f8f003' 
  where SERVICE_ID='075d7a58-7fad-4e1d-9822-83a2fa1a0d05';
  </code></pre>
  <p>I am getting below error:</p>
  <blockquote>
  <p>Error starting at line : 5 in command - update
  ncl_getafix.service_graph set
  Associated_ids=Associated_ids+','+'95d4980b-d12c-4854-97c6-bd9854f8f003'
  where SERVICE_ID='075d7a58-7fad-4e1d-9822-83a2fa1a0d05'
  Error report - ORA-01722: invalid number.</p>
  </blockquote>
  <p>Can anyone help to debug this.</p>