Обсуждение: PostgreSQL JDBC Driver versus Encoding

João Paulo Pires wrote:

> I have a PostgreSQL database which encoding is SQL_ASCII.

This is the cause of your problem. SQL_ASCII provides essentially no
encoding information at all, so the JDBC driver does not know how to
translate between the database and Java's internal UTF-16
representation. If you are going to be inserting anything other than
7-bit-ASCII text into it, you are going to have problems.

If you can, try using a database encoding that can represent the data
you are inserting. UTF8 / UNICODE is probably a good choice unless you
have special requirements. See
http://www.postgresql.org/docs/8.2/static/multibyte.html especially the
bit that says:

> The SQL_ASCII setting behaves considerably differently from the other settings. When the server character set is
SQL_ASCII,the server interprets byte values 0-127 according to the ASCII standard, while byte values 128-255 are taken
asuninterpreted characters. No encoding conversion will be done when the setting is SQL_ASCII. Thus, this setting is
notso much a declaration that a specific encoding is in use, as a declaration of ignorance about the encoding. In most
cases,if you are working with any non-ASCII data, it is unwise to use the SQL_ASCII setting, because PostgreSQL will be
unableto help you by converting or validating non-ASCII characters. 

-O

João Paulo Pires wrote:
>
> Hello,
>
>
>
> I have a PostgreSQL database which encoding is SQL_ASCII.
>
> I inserted information into that database from a MySQL database, using
> Java code, which encoding is UTF-8, and the information in the
> destination database has some strange characters related with encoding
> problems.
>
>
>
> There is any additional parameter that we can consider in the
> PostrgreSQL connection string to deal with those problems?
>
> The problem should be related with the encoding used to connect to
> MySQL database?
>
>
>
you can't encode all symbols in UTF-8 with simple ASCII.   Symbols that
are the same will translate but ASCII only has 200 or so glyphs.  you'll
need to convert the database to UTF-8, then redo your inserts.