Build a Simple VCL Application for IBM Informix Data

Embarcadero RAD Studio provides a development environment for Delphi and C++Builder applications. With the CData ODBC Driver for IBM Informix, you gain access to live IBM Informix data within RAD Studio, abstracting the data into tables, views, and stored procedures that can be used to retrieve and update IBM Informix data. This article will walk through connecting to IBM Informix and creating a simple VCL application with the Form Designer.

Create a Connection to IBM Informix 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.

Set the following properties to connect to IBM Informix

• Server: Set this to the name of the server running IBM Informix.
• Port: Set this to the port the IBM Informix server is listening on.
• Database: Set this to the name of the IBM Informix database.
• User: Set this to the username of a user allowed to access the database.
• Password: Set this to the password of a user allowed to access the database.

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

Create VCL Applications with Connectivity to IBM Informix Data

Follow the procedure below to start executing queries to IBM Informix 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 IBM Informix 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, Price FROM Books WHERE Category = 'US'
   • 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.

You now have an executable application that displays the results of the SQL Query set in the TFDQuery object.