Setting Oracle Language Parameters for DG4ODBC
In response to customer queries, this document describes how to set the
HS_NLS_NCHAR parameters when using DG4ODBC.
If you are using a Unicode* ODBC driver such as the SQL Server ODBC driver, ensure these parameters and values are present in your DG4ODBC init file:
HS_LANGUAGE = language_territory.code_page HS_NLS_NCHAR = UCS2
Replace language, territory and code_page with the Oracle® language, territory and code page that correspond with your databases's language, locale and code page.
For example, if your database is SQL Server, and its language and code page are
English (United States) and
HS_LANGUAGE parameter would look like this:
HS_LANGUAGE = ENGLISH_AMERICA.WE8MSWIN1252
HS_NLS_NCHAR parameter value tells DG4ODBC to pass UCS-2 encoded data to the Unicode ODBC APIs, which is the character encoding the ODBC standard states should be used and is therefore the one that the unixODBC Driver Manager expects.
Ensure also that you have set
NLS_LANG before starting your Oracle® application.
NLS_LANG lets Oracle® know what character set your client machine is using. For example:
$ echo $LANG en_US.UTF-8 $ NLS_LANG=AMERICAN_AMERICA.AL32UTF8 ./sqlplus
If you are using an ANSI ODBC driver (which does not support wide ODBC API calls), you need to specify a non UTF-8 character set in the
HS_LANGUAGE value. For example,
HS_LANGUAGE = AMERICAN_AMERICA.WE8ISO8859P1. If you do not do this and your Oracle® database's
NLS_CHARACTERSET value is set to a UTF-8 encoding, for example
- Uses the Unicode ODBC APIs, for example,
SQLDriverConnectW, which the unixODBC Driver Manager maps to their ANSI equivalent (or if your
HS_FDS_SHAREABLE_NAMEparameter points to the ODBC driver shared object, causes the connection to fail with an "undefined symbol" error).
- Passes UTF-8 encoded data to the ODBC APIs, which the unixODBC Driver Manager does not support. The connection fails because DG4ODBC passes a UTF-8 encoded connection string to
SQLDriverConnectW, which the unixODBC Driver Manager is unable to handle.
Unicode ODBC Drivers*
Unicode ODBC drivers support the wide ODBC APIs, which are of the form SQLxxxW. To check whether your ODBC driver supports wide ODBC APIs, either check with your driver vendor, or, enable ODBC driver logging, connect with DG4ODBC and examine the resultant log file. For example:
$ more /etc/odbc.ini [SQLSERVER_SAMPLE] . . . Logging=Yes LogFile=/tmp/mssql.log $ ./sqlplus / as sysdba $ select * from mytable@mssqllink; $ exit $ more /tmp/mssql.log . . . ENTRY: SQLGetInfoW: connection_handle...