Using a Prepared SQL Statement
A prepared statement should be used in cases where a particular SQL statement is used frequently. The prepared statement is more expensive to set up but executes faster than a statement. This example demonstrates a prepared statement for getting all rows from a table called ``mytable'' whose column COL_A equals ``Patrick Chan''. This example also demonstrates a prepared statement for updating data in the table. In particular, for all rows whose column COL_B equals 123, column COL_A is set to ``John Doe''. 

 try {
   // Retrieving rows from the database.
   PreparedStatement stmt = 
     connection.prepareStatement(
       "SELECT * FROM mytable WHERE COL_A = ?");
   int colunm = 1;
   stmt.setString(colunm, "Patrick Chan");
   ResultSet rs = stmt.executeQuery();
     
   // Updating the database.
   stmt = connection.prepareStatement(
     "UPDATE mytable SET COL_A = 
       ? WHERE COL_B = ?");
   colunm = 1;
   stmt.setString(colunm, "John Doe");
   colunm = 2;
   stmt.setInt(colunm, 123);
   int numUpdated = stmt.executeUpdate();
 } catch (SQLException e) {
 }