A PostgreSQL Interface for PingOne Data using the CData ODBC Driver

There are a vast number of PostgreSQL clients available on the Internet. From standard Drivers to BI and Analytics tools, PostgreSQL is a popular interface for data access. Using the SQL Gateway included in our ODBC Drivers, you can now create PostgreSQL entry-points that you can connect to from any standard client.

To access PingOne data as a PostgreSQL database on Windows, use the CData SQL Gateway, the ODBC Driver for PingOne, and the MySQL foreign data wrapper from EnterpriseDB. In this article, we compile the foreign data wrapper in Visual Studio, install it as an extension, and query PingOne data from PostgreSQL Server.

Configure the Connection to PingOne

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

To connect to PingOne, configure these properties:

• : The region where the data for your PingOne organization is being hosted.
• : The type of authentication to use when connecting to PingOne.
• Either (required when using the default PingOne domain) or , configured as described below.

Configuring WorkerAppEnvironmentId

is the ID of the PingOne environment in which your Worker application resides. This parameter is used only when the environment is using the default PingOne domain (auth.pingone). It is configured after you have created the custom OAuth application you will use to authenticate to PingOne, as described in Creating a Custom OAuth Application in the Help documentation.

First, find the value for this property:

1. From the home page of your PingOne organization, move to the navigation sidebar and click Environments.
2. Find the environment in which you have created your custom OAuth/Worker application (usually Administrators), and click Manage Environment. The environment's home page displays.
3. In the environment's home page navigation sidebar, click Applications.
4. Find your OAuth or Worker application details in the list.
5. Copy the value in the Environment ID field. It should look similar to:
   

   WorkerAppEnvironmentId='11e96fc7-aa4d-4a60-8196-9acf91424eca'

Now set to the value of the Environment ID field.

Configuring AuthorizationServerURL

is the base URL of the PingOne authorization server for the environment where your application is located. This property is only used when you have set up a custom domain for the environment, as described in the PingOne platform API documentation. See Custom Domains.

Authenticating to PingOne with OAuth

PingOne supports both OAuth and OAuthClient authentication. In addition to performing the configuration steps described above, there are two more steps to complete to support OAuth or OAuthCliet authentication:

• Create and configure a custom OAuth application, as described in Creating a Custom OAuth Application in the Help documentation.
• To ensure that the driver can access the entities in Data Model, confirm that you have configured the correct roles for the admin user/worker application you will be using, as described in Administrator Roles in the Help documentation.
• Set the appropriate properties for the authscheme and authflow of your choice, as described in the following subsections.

OAuth (Authorization Code grant)

Set to OAuth.

Desktop Applications

Get and Refresh the OAuth Access Token

After setting the following, you are ready to connect:

• : GETANDREFRESH. To avoid the need to repeat the OAuth exchange and manually setting the each time you connect, use .
• : The Client ID you obtained when you created your custom OAuth application.
• : The Client Secret you obtained when you created your custom OAuth application.
• : The redirect URI you defined when you registered your custom OAuth application. For example: https://localhost:3333

When you connect, the driver opens PingOne's OAuth endpoint in your default browser. Log in and grant permissions to the application. The driver then completes the OAuth process:

1. The driver obtains an access token from PingOne and uses it to request data.
2. The OAuth values are saved in the location specified in , to be persisted across connections.

The driver refreshes the access token automatically when it expires.

For other OAuth methods, including Web Applications, Headless Machines, or Client Credentials Grant, refer to the Help documentation.

Start the Remoting Service

The MySQL remoting service is a daemon process that listens for clients' incoming MySQL connections. See the setup guide in the SQL Gateway overview to configure the MySQL Remoting service in the CData SQL Gateway.

Build the MySQL Foreign Data Wrapper

The Foreign Data Wrapper can be installed as an extension to PostgreSQL, without recompiling PostgreSQL. If you are running PostgreSQL on a Unix-based system, you can use the PostgreSQL Extension Network (PGXN) to install the FDW, mysql_fdw. If you are running PostgreSQL on Windows, compile the extension to ensure that you are working with the latest version. Follow the steps below to make the necessary modifications to build the extension from Visual Studio:

Obtain Prerequisites

To build the foreign data wrapper, do the following:

• Install PostgreSQL. This example uses an installation of PostgreSQL 9.4.
• Obtain the source for the mysql_fdw foreign data wrapper from EnterpriseDB.
• Install MySQL Connector C. This example uses an installation of MySQL Connector C 6.1.

Configure a Project

After you have obtained the necessary software and source code, you are ready to compile the extension with Visual Studio. Follow the steps below to create a project using the mysql_fdw source:

1. In Visual Studio, create a new empty C++ project.
2. In Solution Explorer, right-click Source Files and click Add -> Existing Item. In the file explorer, select all of the .c and .h files from the mysql_fdw source.

Follow the steps below to configure your project:

1. If you are building for a 64-bit system, click Build -> Configuration Manager and in Active Solution Platform select x64.
2. Right-click your project and click Properties.
3. In the Configuration menu, select All Configurations.
4. In Configuration Properties -> General -> Configuration Type, select Dynamic Library.
5. In Configuration Properties -> C/C++ -> Code Generation -> Enable C++ Exceptions, select No.
6. In Configuration Properties -> C/C++ -> Advanced -> Compile As, select Compile as C Code.
7. In Linker -> Manifest File -> Generate Manifest, select No.

Follow the steps below to add the required dependencies:

1. In Linker -> Input -> Additional Dependencies, select Edit and enter the following:

   postgres.lib
   libmysql.lib
   WS2_32.lib
   Secur32.lib
   

   Additionally, ensure that Inherit From Parent or Project Defaults is checked.
2. In Linker -> General -> Additional Library Directories, select Edit and add
   • the path to the lib folder in your PostgreSQL installation
   • the path to the lib folder for your MySQL Connector C installation
3. In Linker -> General -> Link Library Dependencies, select No.
4. To complete the configuration of your project, add the necessary includes: In C/C++ -> General -> Additional Include Directories, add the following folders in the following order:

   MyMySQLConnectorCInstallation\include
   MyPostgreSQLInstallation\MyPostgreSQLVersion\include\server\port\win32_msvc
   MyPostgreSQLInstallation\MyPostgreSQLVersion\include\server\port\win32
   MyPostgreSQLInstallation\MyPostgreSQLVersion\include\server
   MyPostgreSQLInstallation\MyPostgreSQLVersion\include
   

Configure mysql_fdw for Windows

After setting up a project, make the following changes to build mysql_fdw in Visual Studio:

1. In mysql_fdw.c, add the following defines:

   #define dlsym(lib, name) (void*)GetProcAddress((HMODULE)lib, name)
   #define dlopen(libname, unused) LoadLibraryEx(libname, NULL, 0)
   

2. In the mysql_load_library definition, delete the following line:

   mysql_dll_handle = dlopen(_MYSQL_LIBNAME, RTLD_LAZY | RTLD_DEEPBIND);
   

3. Add the following line in the mysql_load_library definition to replace the assignment of mysql_dll_handle for a Windows build:

   mysql_dll_handle = dlopen("libmysql.dll", 0);
   

4. Prepend the call to the mysql_fdw_handler function with the __declspec(dllexport) keyword to export the function from the DLL:

   __declspec(dllexport) extern Datum mysql_fdw_handler(PG_FUNCTION_ARGS);

5. In option.c, prepend the declaration of the mysql_fdw_validator function with the __declspec(dllexport) keyword to export the function from the DLL:

   __declspec(dllexport) extern Datum mysql_fdw_validator(PG_FUNCTION_ARGS);

You can now select the Release configuration and build.

Install the Extension

After you have compiled the DLL, follow the steps below to install the extension:

1. Add the path to the lib folder for MySQL Connector C to the PATH environment variable of the machine running PostgreSQL.
2. Copy the DLL from the RElease folder for your project into the lib subfolder of your PostgreSQL installation.
3. In the folder containing the mysql_fdw csource files, copy myswl_fdw--1.0.sql and mysql_fdw.control into the extension folder under the share folder of your PostgreSQL installation. For example: C:\Program Files\PostgreSQL\9.4\share\extension.

Query PingOne Data as a PostgreSQL Database

After you have installed the extension, follow the steps below to start executing queries to PingOne data:

1. Log into your PostgreSQL database. For example:

   C:\> psql -U postgres
   

2. Load the extension for the database:

   postgres=#CREATE EXTENSION mysql_fdw;
   

3. Create a server object for PingOne data:

   postgres=# CREATE SERVER PingOne FOREIGN DATA WRAPPER mysql_fdw OPTIONS (host
   '127.0.0.1', port '3306');
   

4. Create a user mapping for the username and password of a user known to the MySQL remoting service. Below are the credentials for the user in the sample configuration of the service:

   postgres=# CREATE USER MAPPING for postgres SERVER PingOne OPTIONS (username
   'admin', password 'test');
   

5. Create the local schema:

   postgres=# CREATE SCHEMA PingOne_db;

6. Import all the tables in the PingOne database you defined:

   postgres=# IMPORT FOREIGN SCHEMA "CData PingOne Sys" FROM SERVER PingOne INTO PingOne_db;
   

You can now execute SELECT commands to PingOne:

postgres=# SELECT * FROM PingOne_db."[cdata].[administrators].users";