title: Not able to update clob field in oracle
body: <p>I have a table which has a clob datatype column. From my java method, I am trying to update the clob column of a row using update statement. The query is executing without any error, but the clob is not updated.
  The same code is working for insert statement.</p>
  
  <p>Java Code used for updating clob column:</p>
  
  <pre><code>w_Sql="UPDATE MYTABLE SET MYCLOB= ? WHERE CHANGEREQD = ?";
  _pstmt = openConnection().prepareStatement(w_Sql);
  Reader reader = new StringReader(clobStr);
  _pstmt.setCharacterStream(1, reader, clobStr.length());
  </code></pre>
  
  <p>Java Code used for inserting clob column:</p>
  
  <pre><code>w_Sql="INSERT INTO MYTABLE VALUES(?,?,?,?,?,?,?,'',?)";
  _pstmt = openConnection().prepareStatement(w_Sql);
  Reader reader = new StringReader(clobStr);
  _pstmt.setCharacterStream(1, reader, clobStr.length());
  </code></pre>
  
  <p>Please help me understand the issue.</p>