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Get the Report →How to Connect to IBM Cloud Object Storage Data in Using Python: 6 Steps
Create Python applications on Linux/UNIX machines with connectivity to IBM Cloud Object Storage data. Leverage the pyodbc module for ODBC in Python.
The rich ecosystem of Python modules lets you get to work quicker and integrate your systems more effectively. With the CData Linux/UNIX ODBC Driver for IBM Cloud Object Storage and the pyodbc module, you can easily build IBM Cloud Object Storage-connected Python applications. This article shows how to use the pyodbc built-in functions to connect to IBM Cloud Object Storage data, execute queries, and output the results.
How to Use the CData ODBC Drivers on UNIX/Linux
The CData ODBC Drivers are supported in various Red Hat-based and Debian-based systems, including Ubuntu, Debian, RHEL, CentOS, and Fedora. There are also several libraries and packages that are required, many of which may be installed by default, depending on your system. For more information on the supported versions of Linux operating systems and the required libraries, please refer to the "Getting Started" section in the help documentation (installed and found online).
1. Install the Driver Manager
Before installing the driver, check that your system has a driver manager. For this article, you will use unixODBC, a free and open source ODBC driver manager that is widely supported.
For Debian-based systems like Ubuntu, you can install unixODBC with the APT package manager:
$ sudo apt-get install unixodbc unixodbc-dev
For systems based on Red Hat Linux, you can install unixODBC with yum or dnf:
$ sudo yum install unixODBC unixODBC-devel
The unixODBC driver manager reads information about drivers from an odbcinst.ini file and about data sources from an odbc.ini file. You can determine the location of the configuration files on your system by entering the following command into a terminal:
$ odbcinst -j
The output of the command will display the locations of the configuration files for ODBC data sources and registered ODBC drivers. User data sources can only be accessed by the user account whose home folder the odbc.ini is located in. System data sources can be accessed by all users. Below is an example of the output of this command:
DRIVERS............: /etc/odbcinst.ini
SYSTEM DATA SOURCES: /etc/odbc.ini
FILE DATA SOURCES..: /etc/ODBCDataSources
USER DATA SOURCES..: /home/myuser/.odbc.ini
SQLULEN Size.......: 8
SQLLEN Size........: 8
SQLSETPOSIROW Size.: 8
2. Install the Driver
You can download the driver in standard package formats: the Debian .deb package format or the .rpm file format. Once you have downloaded the file, you can install the driver from the terminal.
The driver installer registers the driver with unixODBC and creates a system DSN, which can be used later in any tools or applications that support ODBC connectivity.
For Debian-based systems like Ubuntu, run the following command with sudo or as root:
$ dpkg -i /path/to/package.deb
For Red Hat systems and other systems that support .rpms, run the following command with sudo or as root:
$ rpm -i /path/to/package.rpm
Once the driver is installed, you can list the registered drivers and defined data sources using the unixODBC driver manager:
List the Registered Driver(s)
$ odbcinst -q -d
CData ODBC Driver for IBM Cloud Object Storage
...
List the Defined Data Source(s)
$ odbcinst -q -s
CData IBMCloudObjectStorage Source
...
To use the CData ODBC Driver for IBM Cloud Object Storage with unixODBC, ensure that the driver is configured to use UTF-16. To do so, edit the INI file for the driver (cdata.odbc.ibmcloudobjectstorage.ini), which can be found in the lib folder in the installation location (typically /opt/cdata/cdata-odbc-driver-for-ibmcloudobjectstorage), as follows:
cdata.odbc.ibmcloudobjectstorage.ini
...
[Driver]
DriverManagerEncoding = UTF-16
3. Modify the DSN
The driver installation predefines a system DSN. You can modify the DSN by editing the system data sources file (/etc/odbc.ini) and defining the required connection properties. Additionally, you can create user-specific DSNs that will not require root access to modify in $HOME/.odbc.ini.
Register a New Instance of Cloud Object Storage
If you do not already have Cloud Object Storage in your IBM Cloud account, follow the procedure below to install an instance of SQL Query in your account:
- Log in to your IBM Cloud account.
- Navigate to the page, choose a name for your instance and click Create. You will be redirected to the instance of Cloud Object Storage you just created.
Connecting using OAuth Authentication
There are certain connection properties you need to set before you can connect. You can obtain these as follows:
API Key
To connect with IBM Cloud Object Storage, you need an API Key. You can obtain this as follows:
- Log in to your IBM Cloud account.
- Navigate to the Platform API Keys page.
- On the middle-right corner click "Create an IBM Cloud API Key" to create a new API Key.
- In the pop-up window, specify the API Key name and click "Create". Note the API Key as you can never access it again from the dashboard.
Cloud Object Storage CRN
If you have multiple accounts, you will need to specify the CloudObjectStorageCRN explicitly. To find the appropriate value, you can:
- Query the Services view. This will list your IBM Cloud Object Storage instances along with the CRN for each.
- Locate the CRN directly in IBM Cloud. To do so, navigate to your IBM Cloud Dashboard. In the Resource List, Under Storage, select your Cloud Object Storage resource to get its CRN.
Connecting to Data
You can now set the following to connect to data:
- InitiateOAuth: Set this to GETANDREFRESH. You can use InitiateOAuth to avoid repeating the OAuth exchange and manually setting the OAuthAccessToken.
- ApiKey: Set this to your API key which was noted during setup.
- CloudObjectStorageCRN (Optional): Set this to the cloud object storage CRN you want to work with. While the connector attempts to retrieve this automatically, specifying this explicitly is recommended if you have more than Cloud Object Storage account.
When you connect, the connector completes the OAuth process.
- Extracts the access token and authenticates requests.
- Saves OAuth values in OAuthSettingsLocation to be persisted across connections.
/etc/odbc.ini or $HOME/.odbc.ini
[CData IBMCloudObjectStorage Source]
Driver = CData ODBC Driver for IBM Cloud Object Storage
Description = My Description
ApiKey = myApiKey
CloudObjectStorageCRN = MyInstanceCRN
Region = myRegion
OAuthClientId = MyOAuthClientId
OAuthClientSecret = myOAuthClientSecret
For specific information on using these configuration files, please refer to the help documentation (installed and found online).
You can follow the procedure below to install pyodbc and start accessing IBM Cloud Object Storage through Python objects.
4. Install pyodbc
You can use the pip utility to install the module:
pip install pyodbc
Be sure to import with the module with the following:
import pyodbc
5. Connect to IBM Cloud Object Storage Data
You can now connect with an ODBC connection string or a DSN. Below is the syntax for a connection string:
cnxn = pyodbc.connect('DRIVER={CData ODBC Driver for IBM Cloud Object Storage};ApiKey=myApiKey;CloudObjectStorageCRN=MyInstanceCRN;Region=myRegion;OAuthClientId=MyOAuthClientId;OAuthClientSecret=myOAuthClientSecret;')
Below is the syntax for a DSN:
cnxn = pyodbc.connect('DSN=CData IBMCloudObjectStorage Sys;')
6. Execute SQL on IBM Cloud Object Storage
Instantiate a Cursor and use the execute method of the Cursor class to execute any SQL statement.
cursor = cnxn.cursor()
Select
You can use fetchall, fetchone, and fetchmany to retrieve Rows returned from SELECT statements:
import pyodbc
cursor = cnxn.cursor()
cnxn = pyodbc.connect('DSN=CData IBMCloudObjectStorage Source;User=MyUser;Password=MyPassword')
cursor.execute("SELECT Key, Etag FROM Objects WHERE Bucket = 'someBucket'")
rows = cursor.fetchall()
for row in rows:
print(row.Key, row.Etag)
You can provide parameterized queries in a sequence or in the argument list:
cursor.execute(
"SELECT Key, Etag
FROM Objects
WHERE Bucket = ?", 'someBucket',1)
Metadata Discovery
You can use the getinfo method to retrieve data such as information about the data source and the capabilities of the driver. The getinfo method passes through input to the ODBC SQLGetInfo method.
cnxn.getinfo(pyodbc.SQL_DATA_SOURCE_NAME)
You are now ready to build Python apps in Linux/UNIX environments with connectivity to IBM Cloud Object Storage data, using the CData ODBC Driver for IBM Cloud Object Storage.