DataBind Controls to Cvent Data in Delphi

The CData ODBC Driver for Cvent supports the ODBC standard to enable integration of live Cvent data with visual form designers and other rapid development tools in Delphi. The ODBC driver simplifies data access strategies for applications that share a single codebase like Delphi by providing a single API for database development. This article shows how to how to connect to Cvent data and query data from a simple visual component library (VCL) application, as well as from Delphi code.

Create a Connection to Cvent Data

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.

Before you can authenticate to Cvent, you must create a workspace and an OAuth application.

Creating a Workspace

To create a workspace:

1. Sign into Cvent and navigate to App Switcher (the blue button in the upper right corner of the page) >> Admin.
2. In the Admin menu, navigate to Integrations >> REST API.
3. A new tab launches for Developer Management. Click on Manage API Access in the new tab.
4. Create a Workspace and name it. Select the scopes you would like your developers to have access to. Scopes control what data domains the developer can access.
   • Choose All to allow developers to choose any scope, and any future scopes added to the REST API.
   • Choose Custom to limit the scopes developers can choose for their OAuth apps to selected scopes. To access all tables exposed by the driver, you need to set the following scopes:

     event/attendees:read	event/attendees:write	event/contacts:read
     event/contacts:write	event/custom-fields:read	event/custom-fields:write
     event/events:read	event/events:write	event/sessions:delete
     event/sessions:read	event/sessions:write	event/speakers:delete
     event/speakers:read	event/speakers:write	budget/budget-items:read
     budget/budget-items:write	exhibitor/exhibitors:read	exhibitor/exhibitors:write
     survey/surveys:read	survey/surveys:write

Creating an OAuth Application

After you have set up a Workspace and invited them, developers can sign up and create a custom OAuth app. See the Creating a Custom OAuth Application section in the Help documentation for more information.

Connecting to Cvent

After creating an OAuth application, set the following connection properties to connect to Cvent:

• InitiateOAuth: GETANDREFRESH. Used to automatically get and refresh the OAuthAccessToken.
• OAuthClientId: The Client ID associated with the OAuth application. You can find this on the Applications page in the Cvent Developer Portal.
• OAuthClientSecret: The Client secret associated with the OAuth application. You can find this on the Applications page in the Cvent Developer Portal.

You can then follow the steps below to use the Data Explorer to create a FireDAC connection to Cvent data.

1. In a new VCL Forms application, expand the FireDAC node in the Data Explorer.
2. Right-click the ODBC Data Source node in the Data Explorer.
3. Click Add New Connection.
4. Enter a name for the connection.
5. In the FireDAC Connection Editor that appears, set the DataSource property to the name of the ODBC DSN for Cvent.

Create VCL Applications with Connectivity to Cvent Data

Follow the procedure below to start executing queries to Cvent data from a simple VCL application that displays the results of a query in a grid.

1. Drop a TFDConnection component onto the form and set the following properties:

   • ConnectionDefName: Select the FireDAC connection to Cvent data.
   • Connected: Select True from the menu and, in the dialog that appears, enter your credentials.

2. Drop a TFDQuery component onto the form and set the properties below:

   • Connection: Set this property to the TFDConnection component, if this component is not already specified.

   • SQL: Click the button in the SQL property and enter a query. For example:

     SELECT Id, Title FROM Events WHERE Virtual = 'true'
   • Active: Set this property to true.

3. Drop a TDataSource component onto the form and set the following property:

   • DataSet: In the menu for this property, select the name of the TFDQuery component.

4. Drop a TDBGrid control onto the form and set the following property:

   • DataSource: Select the name of the TDataSource.
5. Drop a TFDGUIxWaitCursor onto the form — this is required to avoid a run-time error.

Execute Commands to Cvent with FireDAC Components

You can use the TFDConnection and TFQuery components to execute queries to Cvent data. This section provides Cvent data-specific examples of executing queries with the TFQuery component.

Connect to Cvent Data

To connect to the data source, set the Connected property of the TFDConnection component to true. You can set the same properties from code:

Create Parameterized Queries

Parameterized resources can improve performance: Preparing statements is costly in system resources and time. The connection must be active and open while a statement is prepared. By default, FireDAC prepares the query to avoid recompiling the same query over and over. To disable statement preparation, set ResourceOptions.DirectExecute to True; for example, when you need to execute a query only once.

Execute a Query

To execute a query that returns a result set, such as a select query, use the Open method. The Open method executes the query, returns the result set, and opens it. The Open method will return an error if the query does not produce a result set.

To execute a query that does not return a result set, such as a delete, use the ExecSQL method. The ExecSQL method will return an error if the query returns a result set. To retrieve the count of affected rows, use the TFD.RowsAffected property.

Related Articles

Below you can find other articles for using the CData ODBC Driver with RAD Studio, Delphi, and C++ Builder.

• DataBind Controls to Cvent Data in C++Builder
• Viewing Cvent Data in RAD Studio Data Explorer
• Build a Simple VCL Application for Cvent Data