I am trying to connect to my Oracle Database with Python.
I am currently using cx_Oracle to connect with it but doesnt work...
#!/usr/bin/python3
import cx_Oracle
dsn_tns = cx_Oracle.makedsn('Host Name', 'Port Number', service_name='Service Name')
conn = cx_Oracle.connect(user=r'user', password='password', dsn=dsn_tns)
c = conn.cursor()
c.execute('select * from person')
conn.close()
Error:
conn = cx_Oracle.connect(user=r'g_user', password='G_user', dsn=dsn_tns)
cx_Oracle.DatabaseError: DPI-1047: Cannot locate a 64-bit Oracle Client library: "libclntsh.so: cannot open shared object file: No such file or directory". See https://cx-oracle.readthedocs.io/en/latest/user_guide/installation.html for help
I went on the Site and found nothing that could help...
Is something in my Code Wrong or is it something else ?
Make sure you have installed the correct oracle client (you can find the oracle client package from here "https://www.oracle.com/in/database/technologies/instant-client/winx64-64-downloads.html" and add the downloaded folder inside the folder where python is installed and then add this location (location of your client package folder) to system's environment variable. Hope that will work.
I suggest you to first check the compatibility of your OS, Python and Oracle Instant Client architecture:
import platform
platform.architecture()
Then, I definitely advise you to set the Oracle Instant Client inside your jupyter notebook:
import os
os.environ["PATH"] = "Complete Location of Instant Client Folder" + ";" + os.environ["PATH"]
Source: cx_Oracle error. DPI-1047: Cannot locate a 64-bit Oracle Client library
Your error is
DPI-1047: Cannot locate a 64-bit Oracle Client library: "libclntsh.so: cannot open shared object file: No such file or directory".
You need the Oracle Linux 64-bit client binaries in your operating system search path before you start the Python process.
The easiest way is to install the free Oracle Instant Client. Use the latest 19c version - it will let you connect to Oracle DB 11.2 or later. The install instructions are at the foot of the download page. If you install the RPMs, everything is configured for you. If you install the ZIPS I prefer setting the library search path with ldconfig which is also shown in the instructions.
Related
I am trying to connect a Firebird database with Python. I already tried it with pyodbc:
import os
import pyodbc
server = '127.0.0.1/3050'
database = 'Databse-Name'
username = 'Username'
password = 'password'
cnxn = pyodbc.connect('DRIVER={Firebird/InterBase(r)
driver};SERVER='+server+';DATABASE='+database+';UID='+username+';PWD='+ password)
cursor = cnxn.cursor()
I get this error:
OperationalError: ('08004', "[08004] [ODBC Firebird Driver]Unable to connect to data source: library 'gds32.dll' failed to load (-904) (SQLDriverConnect); [08004] [ODBC Firebird Driver]Invalid connection string attribute (0)")
I am not sure why he tries to find 'gds32.dll'. In the ODBC-Connection I used this driver C:\Program Files (x86)\assfinet ams.5\BIN\FB30\x64\fbclient.dll
I am using Firebird as a 64-bit version, so I am a bit clueless because of the 32 in 'gds32.dll'.
I am not sure, if it is the right way to try it with pyodbc. I am open for other advice.
Has anyone an idea why it is not working?
The fact the error mentions gds32.dll means it tried to load fbclient.dll, and that didn't work. Then it tried to fallback to gds32.dll. The gds32.dll is supported historically, because Firebird was forked from InterBase 22 years ago, and InterBase used the name gds32.dll for its client library. The 64-bit version is also called gds32.dll.
The problem is that, unless the C:\Program Files (x86)\assfinet ams.5\BIN\FB30\x64\ folder is explicitly on the path, or you configured the CLIENT connection property, that no library is found (or possibly it's 32-bit not 64-bit).
You need a 64-bit fbclient.dll. If that C:\Program Files (x86)\assfinet ams.5\BIN\FB30\x64\ is really a 64-bit Firebird (then C:\Program Files (x86) is the wrong location), you either need to specify the path of the 64-bit client library in the CLIENT connection property, or you can install it with - from a command prompt started as administrator - instclient i f from a Windows 64-bit Firebird installation, or do a client install using a Firebird installer. Alternatively, you can download the zipkit of a Windows 64-bit Firebird and use its fbclient.dll.
You should also consider using one of the Firebird drivers for Python, instead of using ODBC. You can choose from:
firebird-driver - uses fbclient.dll
FDB - uses fbclient.dll (deprecated and replaced by firebird-driver)
firebirdsql (aka pyfirebirdsql) - a pure Python driver (no native dependencies)
Also, I'm not sure if Gordon's advice about using SQLAlchemy is correct, but I'd recommend investigating that (though below the covers SQLAlchemy will probably use FDB or maybe firebird-driver, so you'd still need a proper 64-bit client library to load).
If you are going to use pandas with a database other than SQLite you should be using SQLAlchemy (ref: here). In your case you would use the sqlalchemy-firebird dialect.
Edit re: comment to original answer
Since we are connecting to localhost we can expect that Firebird has been installed and therefore the client tools are available (which is true for a default install). In that case, the following works on a Windows 8.1 test machine:
import pandas as pd
import sqlalchemy as sa
# note the r"" string
engine = sa.create_engine(r"firebird://SYSDBA:masterkey#localhost/C:\ProgramData\assfinet\assfinet ams.5\Individuell 2022\DB0 - Stand 2022_02-10.FDB")
df = pd.read_sql_query("SELECT * FROM my_table", engine)
although a better approach would be to build the connection URL like this
connection_url = sa.engine.URL.create(
"firebird",
username="SYSDBA",
password="masterkey",
host="localhost",
database=r"C:\ProgramData\assfinet\assfinet ams.5\Individuell 2022\DB0 - Stand 2022_02-10.FDB",
)
engine = sa.create_engine(connection_url)
I have installed cx_oracle(python3) and instant client 21_1 inside a container. When I try to first time I got this error
Cannot locate a 64-bit Oracle Client library: "/python-
env/instantclient_21_1/lib/libclntsh.so:
So I have created lib under /python-env/instantclient_21_1/ and tried again, now I'm getting this error
cx_Oracle.DatabaseError: DPI-1047: Cannot locate a 64-bit Oracle Client library: "libnnz19.so: cannot open shared object file: No such file or directory". See https://cx-oracle.readthedocs.io/en/latest/user_guide/installation.html for help
I don't understand where is it searching for the that so file. It is already present in /python-
env/instantclient_21_1/lib/
Please help
Follow the Instant Client installation steps or cx_Oracle Installation steps and use ldconfig to set the library path to include the Instant Client directory.
You could set DPI_DEBUG_LEVEL=64 (see here) to trace how cx_Oracle is looking for the libraries.
Also see Docker for Oracle Database Applications in Node.js and Python.
I am unable to connect to our enterprise Oracle Db using python 3/cx_Oracle.
Installed are:
python 3 -32 bit
cx_Oracle
Oracle Client 12.1.0.2.0
My connection string attempt is:
import cx_Oracle
conn = cx_Oracle.connect(user='user', password='pwd', dsn='working_dsn')
My PATH variable includes the direct path to my working Oracle library (works using SQL Dev
Error message is:
cx_Oracle.DatabaseError: DPI-1050: Oracle Client library is at version 0.0 but must be at version 11.2 or higher
I have researched the Orcale installation instructions and have found no way to connect. I have previously tried with no success, had my computer reimaged and Oracle reinstalled to ensure only one version of Oracle and still no success. I need to move from R to Python and this is the last piece I need to make the switch. I am able to connect with R using JDBC driverclass/dbConnect.
If cx_Oracle wont work, is there another option for connecting to Oracle from Python3?
Any thoughts suggestions or places to look? Other connection types used?
Thanks in advance.
pip3 install cx_Oracle
first method：
db = cx_Oracle.connect('root/root#localhost: 1523/orcl')
Second method：
db = cx_Oracle.connect('root/root#localhost: 1523/orcl')
Third method
makedsn(IP/HOST, PORT, TNSNAME)
dsn = cx_Oracle.makedsn('localhost','1523','orcl')
db = cx_Oracle.connect('root','root',dsn)
The error you are getting suggests that you have an older version of the Oracle client installed on your machine. Search the directories of your PATH environment variable for OCI.DLL. If you find an older version you'll need to remove or rename it -- just be aware that whatever application put the file there will stop working!
Another possibility is to go to a command prompt and do the following
PATH=my_path_to_instant_client;%PATH%
python test_connect.py
Finally, make sure that if your Python is 32-bit, so is your instant client installation, and if your Python is 64-bit, make sure that your instant client installation is also 64-bit.
Some days ago, I was asked to develop a Python application capable of connecting to a Oracle DB. Since I already have an Oracle client installed (version 12.2.0), I just pip installed cx_Oracle and tried to establish a connection using below code:
import pandas as pd
import cx_Oracle
connection = cx_Oracle.connect('username/password#service_as_described_in_tnsnames.ora')
cur=connection.cursor()
input("Press Enter to continue...")
cur.execute('select* from MY_PRETTY_TABLE')
for line in cur:
print()
cur.close()
connection.close()
But when trying to run it, I got the error "DPI-1050: Oracle Client library must be at version 11.2 or higher". After googling it, I found this answer, and tried to change my code to:
my_dsn = cx_Oracle.makedsn("host",port,sid="sid")
connection = cx_Oracle.connect(user="user", password="password", dsn=my_dsn)
cursor = connection.cursor()
querystring = "SQL query"
cursor.execute(querystring)
But still, same error. It's important to notice that I have already used Oracle DB client in this same machine, to connect a DB with Power BI.
Also, if it can be helpful, my paths are setted as:
C:\instantclient_12_1
C:\Users\oracle2\product\12.1.0\client_1
C:\Users\oracle2\product\12.1.0\client_1\bin
C:\Users\oracle\product\12.2.0\dbhome_1\bin
That error implies that you have another older version of the Oracle client installed somewhere earlier in your PATH. You should do a search for OCI.DLL on your machine (using where.exe or the dir command) and either move or remove any unnecessary copies or adjust PATH as needed. Some older applications stuffed OCI.DLL in C:\Windows\System32 improperly, for example.
This problem had to do with Oracle Instant client Version 19.3.0.0.0.
I uninstalled it and installed the previous version Oracle Instant client 12.2.0.1.0 to and it worked.
https://www.oracle.com/database/technologies/instant-client/winx64-64-downloads.html
Important things to do before you try above:
From Windows command prompt
c:> where oci.dll
make sure you find only one entry and remove the redundant ones.
Ensure you set the environment path to the newly installed client.
At work we have Oracle 7. I would like to use python to access the DB.
Has anyone done that or knows how to do it?
I have Windows XP, Python 2.6 and the cx_oracle version for python 2.6
However, when I try to import cx_oracle i get the following error:
ImportError: DLL load failed the module could not be found
Any help is appreciated!
Matt
cx_Oracle is currently only being provided with linkage to the 9i, 10g, and 11i clients. Install one of these clients and configure it to connect to the Oracle 7 database using the proper ORACLE_SID.
Make sure you have the location of the oracle .dll (o files set in your PATH environment variable. The location containing oci.dll should suffice.
I was running into that same problem at work. I finally dropped trying to use cx_Oracle and went with adodbapi. It worked with Oracle 8.
If you have ODBC configured then you can use it. It is available with ActivePython or as win32 extensions. You will obtain connection with:
connection = odbc.odbc('db_alias/user/passwd')
Optionally you can use Jython and thin JDBC client. Instalation of client is not required. With Jython you have access to db via db url:
db = DriverManager.getConnection(db_url, usr, passwd)
where db_url looks like:
jdbc:oracle:thin:user/passwd#machine_ip:port:dbname