DPI-1049 symbol OCIClientVersion not found in OCI library

[nmmassey2]

I've installed Python, Oracle Instant Client (12.2) and cx_Oracle (using pip) onto a 32-bit windows 7 machine and am trying to connect my python instance to my Oracle database. When I try to connect using the following code

import cx_Oracle
cx_Oracle.clientversion()

db1 = cx_Oracle.connect('username/pw//hostURL:port/serviceName')

, I receive the following error:
"DatabaseError: DPI-1049: symbol OCIClientVersion not found in OCI library"

I've installed the appropriate instant client containing the .dll files needed. I've set the PATH variable to point to this folder. Could you please advise how to connect?

Thank you!

[cjbj]

• Do you have other (older) Oracle software on the machine? Make sure Instant Client is first in PATH when you actually run Python. Restarting the terminal or similar may be necessary.

• While you're checking, verify you installed the correct VS redistributable for 12.2.

[nmmassey2]

I rearranged the PATH variable to point to the Instant Client 12.2 first, and have installed the VS 2013 distributable per documentation. Still receiving the same error code.

I do have OraClient11g installed on my computer, but I only use the latest version of Oracle SQL Developer. Should I uninstall the older version? (Update -- uninstalled 11g and still receiving the same error code)

[crisansou]

I got the same error, I've installed the Oracle Developer Suite, so I don't need a client. Do you know what is the problem? Below are the settings:

1) Environment variables

a) PATH: "D:\DevSuiteHome\bin"
b) TNS_ADMIN: "D:\DevSuiteHome\NETWORK\ADMIN"

2) Code

import cx_Oracle

uid = "user"
pwd = "password"
db = "IP:1530"

connection = cx_Oracle.connect(uid + "/" + pwd + "@" + db)
cursor = connection.cursor()

cursor.execute("SELECT * FROM TABLE")
result = cursor.fetchone()
if result == None:
print("No results")
exit
else:
while result:
print(result)
result[0]
result = cursor.fetchone()

cursor.close()
connection.close()

After execution was displayed this message:

"Traceback (most recent call last):
line 8, in connection = cx_Oracle.connect(uid + "/" + pwd + "@" + db)
cx_Oracle.DatabaseError: DPI-1049: symbol OCIClientVersion not found in OCI library

Process finished with exit code 1"

[anthony-tuininga]

What version of the Oracle Developer Suite do you have installed? cx_Oracle requires an Oracle client of 11.2 or higher. Can you install an instant client and ensure that it is first in the PATH environment variable?

[crisansou]

Anthony, thank you for your answer but unfortunately didn't work.

I use Oracle Developer Suite 10g and database 11.2.0.4.0, as you suggested I downloaded an client ("instantclient-basic-windows.x64-11.2.0.4.0.zip") and unzip in directory C:.

I changed the environment variables and restarted the machine, but the problem continues:

a) PATH: "C:\instantclient_11_2;D:\DevSuiteHome\bin;C:\ProgramData\Oracle\Java\javapath;c:\Rtools\bin;"
b) TNS_ADMIN: "C:\instantclient_11_2"

[anthony-tuininga]

Did you confirm that the environment variables are set as expected before running Python and importing cx_Oracle? If you set the environment variables in the GUI, you have to restart your command prompt to ensure that the new values are in place.

Also, are you using 32-bit Python or 64-bit Python?

[crisansou]

Yes, first I changed the environment variables and then restarted the system. I use 32-bit Python, but the machine is 64-bit.

[anthony-tuininga]

If you are using 32-bit Python, then you also must use a 32-bit instant client. But the instant client you downloaded was 64-bit! That will get ignored. Either use 64-bit Python or download a 32-bit instant client. You can't mix and match 32-bit and 64-bit software!

[anthony-tuininga]

BTW, you can use a 12.2 client to connect to an 11.2 database. You don't have to use the 11.2 client!

[crisansou]

Thanks for the information! I'll reinstall the Python, in the first time I chose the main site option (python-3.6.3.exe).

[anthony-tuininga]

You're welcome. Let us know if you are able to get the issue resolved. Thanks!

[crisansou]

Anthony,

I installed Anaconda 64 bits to study Data Science and after changing the code as below I was able to connect in the database, thanks!

import cx_Oracle

uid = "user"
pwd = "password"
dsnStr = cx_Oracle.makedsn("IP", "1530","dbdev01")

connection = cx_Oracle.connect(user=uid, password=pwd, dsn=dsnStr)

[anthony-tuininga]

Glad you got it figured out. I'll mark this as closed, then!