PreparedStatement & regular Statement - different results for same select

Question

I was wondering if someone could either
i) try this out for me to confirm my results or
ii) let me know what I am doing wrong
I'm one of the developers on a product and am currently investigating localization for the Thai language...just checking to see that Java and Swing have no problems with it. The only bewildering thing which has happened is noticing that some values which are fetched from the database display in Thai perfectly and other values display as a garble. Sometimes the exact same column is displayed correctly in one part of the program but is not OK in another part. I think I've figured out what it going on and suspect a bug in Oracle's JDBC:
Some selects were configured as PreparedStatements and those return the Thai properly. The more common case however was for programmers to use a simple Statement object for their select and it is in those that the multi-byte strings don't get returned properly.
The following code shows the problem that I am experiencing. I am basically executing the exact same select in 2 different ways and they are both giving different results as long as the column being queried contains a Thai character. If someone could grab and check it out and let me know if they see the same thing, I'd appreciate it. Just change the column/table name and the username/password/databaseIP to get it to run.
<code>
import java.sql.*;
public class SelectTest {
public static void main(String[] args) {
try {
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
Connection conn = DriverManager.getConnection( "jdbc:oracle:thin:@10.4.31.168:1524:ora8",
"dms_girouard",
"girouard");
String sqlCommand = "select C0620_Title from T0620_SwSheet";
Statement statement = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
ResultSet resultSet1 = statement.executeQuery(sqlCommand);
while (resultSet1.next()) {
if (resultSet1.getString("C0620_Title") != null) {
System.out.println("resultSet1 Title = " + resultSet1.getString("C0620_Title"));
PreparedStatement preparedStatement = conn.prepareStatement(sqlCommand);
ResultSet resultSet2 = preparedStatement.executeQuery();
while (resultSet2.next()) {
if (resultSet2.getString("C0620_Title") != null) {
System.out.println("resultSet2 Title = " + resultSet2.getString("C0620_Title"));
catch (Exception e) {
System.out.println(e.getMessage());
</code>

Answer 1

Hi Peter,
Are you using NCHAR column for Thai , or is your database character set set for Thai.
If you are using a NCHAR column for holding Thai data, then you have to use the
OraclePreparedStatement.setFormOfUse(...) before executing the select.
Regards
Elango. Hi Elangovan,
Thank you for answering.
The datatype on the column is VARCHAR2.
I did my initial tests without doing anything special to make sure the database is localized for Thai, and I was happy to find that almost everything still worked fine - I was able to save and retrieve Thai strings to the database almost perfectly.
The only problem I discovered was the difference between Statement and PreparedStatement selects on a column containing Thai. Colleagues of mine have said they see the same thing when testing on a Oracle database which has been configured specifically for the Thai customer.
I read somewhere that the current JDBC drivers are using an older version of the Unicode standard than the most current version of the Java SDK and that it was causing some problems with Korean. I'm wondering if maybe it's the same problem with Thai.