What's causing 'unable to connect to data source' for pyodbc?

Question

I\'m trying to connect to an MSSQL database from python on Linux (SLES).

I have installed pyodbc and Free TDS. From the command line:

tsql -H server          


        

Answer 1

I had the same problem and I found out that it was missing the TDS_Version parameter in the call to connect(). The following code works for me to connect to an instance of MS SQL Server 2008:

import pyodbc

driver = '/opt/local/lib/libtdsodbc.so' # Change this to where FreeTDS installed the driver libaray!

conn = pyodbc.connect(
    driver = driver,
    TDS_Version = '7.2', # Use for
    server = '<hostname or ip address>',
    port = 1433,
    database = '<database>',
    uid = '<uid>',
    pwd = '<pwd>')

Answer 2

One setting is enoug, /etc/odbcinst.ini:

[FreeTDS]
Description = FreeTDS Driver to MsSQL
Driver = /usr/lib/x86_64-linux-gnu/odbc/libtdsodbc.so
UsageCount = 1

And next:

connection = pyodbc.connect(
    'DRIVER=FreeTDS;'
    'SERVER=<host_name_or_ip>;'
    'PORT=1433;'
    'DATABASE=<database>;'
    'UID=<username>;'
    'PWD=<password>;'
    'TDS_VERSION=8.0;'
)

Answer 3

Just for an extra datapoint, odbc.ini is empty on my host, and odbcinst.ini has the following lines:

# Driver from FreeTDS
#
[FreeTDS]
Driver = /usr/lib64/libtdsodbc.so.0

last, the freetds.conf file has these lines:

[global]
    host= <hostname>
    port= <mssql port>
    tds version = 8.0

While one can certainly specify option settings in odbc.ini, doing it this way allows the configuration options to all be managed where you'd expect them -- the freetds.conf file.

Answer 4

This worked for me, not sure but thought that it might help someone

run below command to find which version of odbcinst and isql you are using

 which odbcinst

 which isql

Then run $ odbcinst -j to find which odbc.ini and odbcinst.ini is getting used.

In odbcinst.ini add

[FreeTDS]
Description=FreeTDS Driver for Linux & MSSQL
Driver=/usr/local/lib/libtdsodbc.so
Setup=/usr/local/lib/libtdsodbc.so
UsageCount=1

And in odbc.ini configure your server as

[YOUR_SERVER]
Driver = FreeTDS
Servername = <YOUR_MACHINE_NAME>
Database = <Database_You_Want_To_Connect>

I found some good description at https://docs.snowflake.net/manuals/user-guide/odbc-linux.html#unixodbc

Also take a look at https://github.com/lionheart/django-pyodbc/wiki/Mac-setup-to-connect-to-a-MS-SQL-Server

Answer 5

Adding TDS_Version to the connection string worked for me:

connection_string = 'DRIVER={{FreeTDS}};SERVER={server};PORT=1433;DATABASE={database};UID={uid};PWD={pwd};TDS_VERSION=8.0'

Answer 6

After hours of going in circles it turns out all I was missing was

TDS_Version = 8.0 in the DSN in my odbc.ini file.

I had specified it elsewhere, but it needed to be here, too, apparently.

Hope this helps some other poor soul.