How to identify Oracle Instant Client in a Django project?-CodePudding

I try to link an external Oracle database on which I have read-only privileges to my Django project and then only send it raw SQL queries.

So I first created a second table in my project settings (because I still need the default database)

settings.py

DATABASES = {
'default': {
    'ENGINE': 'django.db.backends.sqlite3',
    'NAME': BASE_DIR / 'db.sqlite3',
},
'oracleDB':{
    'ENGINE': 'django.db.backends.oracle',
    'NAME': 'my_dsn',
    'USER': 'my_user',
    'PASSWORD': 'my_password',
    'HOST': 'my_host',
    'PORT': 'my_port',
    'OPTIONS':{
        'threaded':True
    }
}

Then in my view I call it this way (seen on a forum):

views.py

from django.db import connections
def my_function(request):
    with connections['oracleDB'].cursor() as cur:
        cur.execute( "SOME SQL QUERY")
        print(cur.fetchall())

And I get this error

DPI-1047: Cannot locate a 64-bit Oracle Client library: “C: ProgramData Oracle12c product 12.1.0 client_1 bin oci.dll is not the correct architecture”. See cx_Oracle 8 Installation — cx_Oracle 8.3.0 documentation for help

I know that I need the Oracle instantclient to connect, I used to use it in connection with the cx_Oracle package and it worked well (so i'm certain the version is good). Except that now I connect with Django and its settings where I can’t specify the path to my Oracle instantclient.

Do you have any idea how to enable Django to detect this client?

I am under Windows 10 64bits.

Thank you in advance, please feel free to ask me to develop

CodePudding user response：

It seems that you might have multiple versions of Oracle libraries installed. As you found, you need to make sure that a 64-bit set of Oracle Client libraries is available to Python. Or alternatively use a 32-bit Python executable.
If you already have the libraries installed on this machine (since you say you can use cx_Oracle directly), then in your Django settings.py file add a call to cx_Oracle.init_oracle_client(lib_dir=r"\path\to\instantclient"). (This technique also works on macOS, but not Linux)
Alternatively, use the new major version of cx_Oracle - which got renamed to python-oracledb, see the release announcement. It doesn't need Oracle Client libraries. See this post.

CodePudding user response：

It’s okay I solved my problem by adding:

settings.py

import cx_Oracle
cx_Oracle.init_oracle_client(lib_dir="my_path_to_oracle_client")
 
DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': BASE_DIR / 'db.sqlite3',
        },
        'oracleDB':{
            'ENGINE':'django.db.backends.oracle',
            'NAME':(
                '(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=my_host)(PORT=my_port))'
                '(CONNECT_DATA=(SERVICE_NAME=my_service)))'
            ),
            'USER':'my_user',
            'PASSWORD':'my_password',
        }

So I added client initialization by cx_Oracle directly in Django’s settings and I modified my NAME that didn’t allow recognition of the database before that.

For the query of the base then I do like this:

views.py

from django.db import connections
 
with connections['oracleDB'].cursor() as cur:
        cur.execute("""MY_SQL_QUERY""")