Build a Simple VCL Application for Greenplum データ

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

Create a Connection to Greenplum データ

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.

Greenplum に接続するには、Server、Port （デフォルトポートは5432）、およびDatabase 接続プロパティを設定して、サーバーへの認証に使用するUser とPassword を設定します。Database プロパティが指定されていない場合、CData 製品はユーザーのデフォルトデータベース（ユーザーと同じ名前になります）に接続します。

You can then follow the steps below to use the Data Explorer to create a FireDAC connection to Greenplum データ.

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 Greenplum.

Create VCL Applications with Connectivity to Greenplum データ

Follow the procedure below to start executing queries to Greenplum データ 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 Greenplum データ.
   • 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 Freight, ShipName FROM Orders WHERE ShipCountry = USA
   • 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.

Related Articles

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

• DataBind Controls to Greenplum データ in C++Builder
• DataBind Controls to Greenplum データ in Delphi
• Viewing Greenplum データ in RAD Studio Data Explorer