python-oracledb (new cx_Oracle) connection generating NotSupportedError DPY-3012 errors-CodePudding

So I am trying the new oracledb python library, which replaces cx_oracle - as I dont want to have to install the oracle instant client.

un             = 'fred'
pwd            = 'mypass'
host           = 'server.mycompany.net'
port           =  1521
service_name   = 'servicea'


params = oracledb.ConnectParams(host=host, port=port, service_name=service_name)

with oracledb.connect(user=un, 
                      password=pwd,
                      params = params
                      ) as connection:
    
    with connection.cursor() as cursor:
        sql = "select * from dim_drug_product"
        for r in cursor.execute(sql):
            print(r)

And I just get this back:

File C:\ProgramData\Anaconda3\envs\ariel\lib\site-packages\oracledb\errors.py:103, in _raise_err(error_num, context_error_message, cause, **args) 101 message = f"{message}\n{context_error_message}" 102 exc_type = ERR_EXCEPTION_TYPES[error_num // 1000] --> 103 raise exc_type(_Error(message)) from cause

NotSupportedError: DPY-3012: national character set id 871 is not supported by python-oracledb in thin mode

CodePudding user response：

The national character set 871 (UTF8, aka CESU-8) is not supported by the thin driver. You will have to either (a) use the thick driver instead or (b) switch to using the character set AL32UTF8, aka UTF-8. If you would like to request support for the older (non-standard) character set you can do so here: https://github.com/oracle/python-oracledb/issues.

CodePudding user response：

What's your database national character set?

SELECT value AS db_ncharset
FROM nls_database_parameters
WHERE parameter = 'NLS_NCHAR_CHARACTERSET';

There is a documented restriction in python-oracledb 1.0.0 about the 'national character set' (aka NCHAR) support: https://python-oracledb.readthedocs.io/en/latest/user_guide/globalization.html#character-sets-and-globalization

If your NCHAR character set isn't supported in Thin mode, then install Instant Client and use thick mode - or update your database to use a different NCHAR character set, or to use a base character set of AL32UTF8 and remove the use of NCHAR columns.