Build a Simple VCL Application for Google Spanner データ

How to build a simple VCL Application to view Google Spanner データ in RAD Studio using the CData ODBC Driver for Google Spanner.

最終更新日:2023-06-12

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

Create a Connection to Google Spanner 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.

GoogleSpanner はOAuth 認証標準を利用しています。各ユーザーやドメイン内のユーザーの代わりに、CData 製品がGoogle API にアクセスすることを許可できます。詳しくは、ヘルプドキュメントの「OAuth の使用」を参照してください。

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

Create VCL Applications with Connectivity to Google Spanner データ

Follow the procedure below to start executing queries to Google Spanner 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 Google Spanner 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 Name, TotalDue FROM Customer
    • 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.

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