Python和Oracle DB-“错误DPI-1050：Oracle客户端库必须为11.2或更高版本”

Question

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

Answer 1

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.

Answer 2

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.