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How to Connect to SingleStore Data in Using Python: 6 Steps


Create Python applications on Linux/UNIX machines with connectivity to SingleStore 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 SingleStore and the pyodbc module, you can easily build SingleStore-connected Python applications. This article shows how to use the pyodbc built-in functions to connect to SingleStore 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 SingleStore ...

List the Defined Data Source(s)

$ odbcinst -q -s CData SingleStore Source ...

To use the CData ODBC Driver for SingleStore with unixODBC, ensure that the driver is configured to use UTF-16. To do so, edit the INI file for the driver (cdata.odbc.singlestore.ini), which can be found in the lib folder in the installation location (typically /opt/cdata/cdata-odbc-driver-for-singlestore), as follows:

cdata.odbc.singlestore.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.

The following connection properties are required in order to connect to data.

  • Server: The host name or IP of the server hosting the SingleStore database.
  • Port: The port of the server hosting the SingleStore database.
  • Database (Optional): The default database to connect to when connecting to the SingleStore Server. If this is not set, tables from all databases will be returned.

Connect Using Standard Authentication

To authenticate using standard authentication, set the following:

  • User: The user which will be used to authenticate with the SingleStore server.
  • Password: The password which will be used to authenticate with the SingleStore server.

Connect Using Integrated Security

As an alternative to providing the standard username and password, you can set IntegratedSecurity to True to authenticate trusted users to the server via Windows Authentication.

Connect Using SSL Authentication

You can leverage SSL authentication to connect to SingleStore data via a secure session. Configure the following connection properties to connect to data:

  • SSLClientCert: Set this to the name of the certificate store for the client certificate. Used in the case of 2-way SSL, where truststore and keystore are kept on both the client and server machines.
  • SSLClientCertPassword: If a client certificate store is password-protected, set this value to the store's password.
  • SSLClientCertSubject: The subject of the TLS/SSL client certificate. Used to locate the certificate in the store.
  • SSLClientCertType: The certificate type of the client store.
  • SSLServerCert: The certificate to be accepted from the server.

Connect Using SSH Authentication

Using SSH, you can securely login to a remote machine. To access SingleStore data via SSH, configure the following connection properties:

  • SSHClientCert: Set this to the name of the certificate store for the client certificate.
  • SSHClientCertPassword: If a client certificate store is password-protected, set this value to the store's password.
  • SSHClientCertSubject: The subject of the TLS/SSL client certificate. Used to locate the certificate in the store.
  • SSHClientCertType: The certificate type of the client store.
  • SSHPassword: The password that you use to authenticate with the SSH server.
  • SSHPort: The port used for SSH operations.
  • SSHServer: The SSH authentication server you are trying to authenticate against.
  • SSHServerFingerPrint: The SSH Server fingerprint used for verification of the host you are connecting to.
  • SSHUser: Set this to the username that you use to authenticate with the SSH server.

/etc/odbc.ini or $HOME/.odbc.ini

[CData SingleStore Source] Driver = CData ODBC Driver for SingleStore Description = My Description User = myUser Password = myPassword Database = NorthWind Server = myServer Port = 3306

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 SingleStore 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 SingleStore 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 SingleStore};User=myUser;Password=myPassword;Database=NorthWind;Server=myServer;Port=3306;')

Below is the syntax for a DSN:

cnxn = pyodbc.connect('DSN=CData SingleStore Sys;')

6. Execute SQL on SingleStore

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 SingleStore Source;User=MyUser;Password=MyPassword') cursor.execute("SELECT ShipName, ShipCity FROM Orders WHERE ShipCountry = 'USA'") rows = cursor.fetchall() for row in rows: print(row.ShipName, row.ShipCity)

You can provide parameterized queries in a sequence or in the argument list:

cursor.execute( "SELECT ShipName, ShipCity FROM Orders WHERE ShipCountry = ?", 'USA',1)

Insert

INSERT commands also use the execute method; however, you must subsequently call the commit method after an insert or you will lose your changes:

cursor.execute("INSERT INTO Orders (ShipCountry) VALUES ('USA')") cnxn.commit()

Update and Delete

As with an insert, you must also call commit after calling execute for an update or delete:

cursor.execute("UPDATE Orders SET ShipCountry = 'USA'") cnxn.commit()

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 SingleStore data, using the CData ODBC Driver for SingleStore.

Ready to get started?

Download a free trial of the SingleStore ODBC Driver to get started:

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Learn more:

SingleStore Icon SingleStore ODBC Driver

The SingleStore ODBC Driver is a powerful tool that allows you to connect with live data from SingleStore, directly from any applications that support ODBC connectivity.

Access SingleStore data like you would a database - read, write, and update SingleStore. through a standard ODBC Driver interface.

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