Re: [JDBC] Using Postgres with Latin1 (ISO8859-1) and Unicode (utf-8)

On Mon, 8 Nov 2004, J. Michael Crawford wrote:
>
> Even in Java, where you can do all sorts of character-encoding
> translation, it can be impossible to translate data retrieved from Postgres
> if it's in the wrong encoding. We've tried changing the JVM encoding,
> altering the jdbc driver, translating encodings on the database read, and
> translating encodings after the read while building a new string, to no
> avail. We tried 25 combinations of each strategy (five different possible
> read encodings and five different possible string encodings), and nothing
> worked. We could get an application working in one JVM with one encoding,
> but another JVM would break, and no amount of translation would help.
>
> But when we finally told Postgres what to return, everythign worked like
> a charm.
>
> Just as with step two, the key is to use the "SET CLIENT_ENCODING TO
> (encoding)" sql command. If you're using an application where you can send
> SQL to the server, this is all you need. In something like MS Access,
> you'll have to move to a passthrough query. For Java, you'll need to send
> a command through JDBC:
>
> String DBEncoding = "Unicode" //use a real encoding, either returned from
> the jvm or explicitly stated
> PreparedStatement statement = dbCon.prepareStatement("SET CLIENT_ENCODING
> TO '" + DBEncoding + "'");
> statement.execute();
>

This is bad advice for a Java client and does not work. The JDBC driver
always expects data in unicode and issues a SET client_encoding of it's
own at connection startup to make sure it gets unicode data. Changing
this to another encoding will break the driver and in the cvs version a
check has been added to error out if it detects you doing this.

Kris Jurka