Python 3和IBM_DB设置问题

Question

I am currently using a Windows 10 machine and Python 3.6.3 and have downloaded and installed the requirements listed here: https://www.ibm.com/support/knowledgecenter/en/SSSNY3_10.1.0/com.ibm.swg.im.dbclient.python.doc/doc/t0054367.html from the following link:

https://www.ibm.com/support/knowledgecenter/en/SSSNY3_10.1.0/com.ibm.swg.im.dbclient.python.doc/doc/r0054697.html

I have installed the ODBC driver (IBM DB2 ODBC Driver) and configured it in my ODBC Data Source Administrator interface on the Windows 10 machine. I have also done this for a SQL Server connection using the appropriate set up for that.

The issue I have is that I am receiving the following error:

Traceback (most recent call last):
  File "C:\Users\<Username>\Python\Test IBM Connection.py", line 6, in <module>
    ibm_db.connect("<DSN>","<Username>","<Password>")
Exception: [IBM][CLI Driver] SQL1531N  The connection failed because the name
specified with the DSN connection string keyword could not be found in either 
the db2dsdriver.cfg configuration file or the db2cli.ini configuration file.  
Data source name specified in the connection string: "<DSN>".
 SQLCODE=-1531

I, of course have googled this issue to no avail. I am new to IBM_DB and it requirements and need help configuring the DSN to work properly.

I have also attempted to run the db2dsdcfgfill - but have been unsuccessful, see here: https://www.ibm.com/support/knowledgecenter/en/SSEPGG_9.5.0/com.ibm.swg.im.dbclient.config.doc/doc/r0054557.html

I am unsure what information needs to be in these files, and where they need to be and how to register them so the system is seeing them.

I have been able to connect and query an SQL Server, but have not been able to connect to the IBM iSeries AS400 system.

I have researched the many parts of the issue I am having but have not found any solutions for my issue.

As requested I have added the following information:

Connection String:

ibm.connect("<DSN>", "<Username>","<Password>")

ODBC Version is 11.01.00.1527

I am connecting to an IBM iSeries database - it running on system i and is running version 7.2

Answer 1

This answer shows some examples of how to use db2cli.exe to configure db2dsdriver.cfg

Remember that you do not need to use DSNs in python to connect to Db2 databases, you can use the long form of the connect to specify all the details of the connection. Using a DSN is useful when the DSN is used by multiple different local applications(so the config is only in one place), or when your python scripts need to run on multiple environments which may use different DSN details without code changes and where the DSNs are under control of a different group, or when DSN-parameters are environment specific. So choose the best approach to suit your enterprise.

If you must use DSNs, choose either user-dsn's or system-dsn as appropriate for your environment and requirements.

Choose which format of configuration file to use for the Db2 client. The db2cli.ini is an old legacy format Windows style INI file with x=y tuples and [section] blocks in plain text. You can manipulate its contents either with a text editor or with command line commands of Db2 . This old format has enough online documentation and has been around for decades, so I won't expand on this.

The db2dsdriver.cfg file is a more recent format. It is an XML file. You can edit it with Db2 commands (db2cli.exe on Windows) or via a text editor (or XML editor). I would use this format for new environments with currently supported Db2 clients. As its XML, there is a validation step (db2cli validate ...).

The online Db2 Knowledge centre has all this information although you do need to spend time studying many pages and rehearse and test carefully.

Here are some sample lines of batch file script, which you can run in an ADMINISTRATOR db2cmd.exe window on MS-windows, which show how to use the db2cli.exe tool to populate db2dsdriver.cfg. You have to have at least local-admin rights to run these commands.

First set some variables to match your specific environment, port-number, hostname of Db2 server, credentials and DSN and remote database name (these 2 can be different values). Then run db2cli to write entries to the db2dsdriver.cfg using the variables previously set, and finally run db2cli to attempt to connect to the DSN. These are trivial examples, in real cases you often need to add many additional parameters to the database section or DSN section (Db2 on different platforms supports many options that you can set at connection time). You set any of these via the db2cli writecfg add syntax, although IBM's documentation is less than helpful in this area. These examples assume your db2dsdriver.cfg is currently empty. You may need additional parameters for connecting to Db2 for i. My examples are for Db2 for LUW. You also need relevant licences. Save the example below to a batch file, change the values to suit your environment, and rehearse on a development or test environment.

set db2_port=port_number_on_which_db2_is_listening

set db2_server=ip_address_or_fqdn_of_db2_server

set db2_id_to_connect=myusername

set db2_id_pwd=password

set dsn_name=sample

set db_name=sample


db2cli writecfg add -dsn %dsn_name% -database %db_name% -host %db2_server% -port %db2_port%  


db2cli writecfg add -database %db_name% -host %db2_server% -port %db2_port% 

db2cli validate -dsn %dsn_name% -connect -user %db2_id_to_connect% -passwd %db2_id_pwd%