Retrieving data from IBM DB2 using pyodbc and the related error - python-3.x

Question

I confirm that I have gone through multiple posts in StackOverflow with respect to similar problem, still stuck with the below problem, hence posting to seek guidance/pointers.
Following is the code
import pypyodbc as pyodbc
import configparser
config = configparser.ConfigParser()
config.read('config.ini')
conn_str = 'DRIVER={' + config['db2']['driver'] + '};' \
+ 'SERVER=' + config['db2']['server'] + ';' \
+ 'DATABASE=' + config['db2']['database'] + ';' \
+ 'UID=' + config['db2']['uid'] + ';' \
+ 'PWD=' + config['db2']['password']
print(conn_str)
connection = pyodbc.connect(
conn_str
)
cur = connection.cursor()
cur.execute('SELECT col_1, col_2 FROM schema.table_name LIMIT 2')
for row in cur:
print (row)
Output from code execution
[connect string output]
DRIVER={'IBM i Access ODBC Driver 64-bit'};SERVER='hostname';DATABASE='database';UID='userid';PWD='password'
[error from executing the code]
raise Error(state,err_text)
pypyodbc.Error: ('IM002', '[IM002] [unixODBC][Driver Manager]Data source name not found, and no default driver specified')
Configuration file
$ cat config.ini
[db2]
driver = 'IBM i Access ODBC Driver 64-bit'
server = 'hostname'
database = 'database'
uid = 'userid'
password = 'password'
Output of ODBC installer and uninstaller command
odbcinst -j
unixODBC 2.3.1
DRIVERS............: /etc/odbcinst.ini
SYSTEM DATA SOURCES: /etc/odbc.ini
FILE DATA SOURCES..: /etc/ODBCDataSources
USER DATA SOURCES..: /home/useradmin/.odbc.ini
SQLULEN Size.......: 8
SQLLEN Size........: 8
SQLSETPOSIROW Size.: 8
cat /etc/odbcinst.ini
[PostgreSQL]
Description=ODBC for PostgreSQL
Driver=/usr/lib/psqlodbcw.so
Setup=/usr/lib/libodbcpsqlS.so
Driver64=/usr/lib64/psqlodbcw.so
Setup64=/usr/lib64/libodbcpsqlS.so
FileUsage=1
[MySQL]
Description=ODBC for MySQL
Driver=/usr/lib/libmyodbc5.so
Setup=/usr/lib/libodbcmyS.so
Driver64=/usr/lib64/libmyodbc5.so
Setup64=/usr/lib64/libodbcmyS.so
FileUsage=1
[IBM i Access ODBC Driver]
Description=IBM i Access for Linux ODBC Driver
Driver=/opt/ibm/iaccess/lib/libcwbodbc.so
Setup=/opt/ibm/iaccess/lib/libcwbodbcs.so
Driver64=/opt/ibm/iaccess/lib64/libcwbodbc.so
Setup64=/opt/ibm/iaccess/lib64/libcwbodbcs.so
Threading=0
DontDLClose=1
UsageCount=1
[IBM i Access ODBC Driver 64-bit]
Description=IBM i Access for Linux 64-bit ODBC Driver
Driver=/opt/ibm/iaccess/lib64/libcwbodbc.so
Setup=/opt/ibm/iaccess/lib64/libcwbodbcs.so
Threading=0
DontDLClose=1
UsageCount=1
$ cat ~/.odbc.ini
[db2]
Driver = IBM i Access ODBC Driver 64-bit
DATABASE = 'database'
SYSTEM = hostname
HOSTNAME = hostname
PORT = 446
PROTOCOL = TCPIP
$ isql db2 $username $password -v
[08001][unixODBC][IBM][System i Access ODBC Driver]The specified database can not be accessed at this time.
[ISQL]ERROR: Could not SQLConnect
I have double checked and confirm that there is no typo with driver name "IBM i Access ODBC Driver 64-bit"
OS information
x86_64 GNU/Linux
Any pointers/guidance on how to debug the issue, please?

Answer 1

I think you are confusing the schema name with the database name.
Odds are you can omit the database name completely (or leave it empty string and let it default to *SYSBAS). Instead, you can specify the DefaultLibraries argument.
See the IBM doc here for info on the valid connection string (and odbc.ini) keywords.
Similarly, you can omit the PORT, PROTOCOL, and HOSTNAME keywords, as they're not supported by this driver.
That will leave you with an odbc.ini that looks as simple as this:
[db2]
Driver = IBM i Access ODBC Driver 64-bit
DefaultLibraries = 'database'
SYSTEM = hostname