各製品の資料を入手。
詳細はこちら →DataBind Controls to Snowflake データ in C++Builder
DataBind to Snowflake のデータ in C++Builder with standard components and controls.
最終更新日:2023-06-12The CData ODBC Driver for Snowflake makes it easy to integrate connectivity to live Snowflake のデータ with standard data access components in C++Builder. This article shows how to create a simple visual component library (VCL) application in C++Builder that connects to Snowflake のデータ, executes queries, and displays the results in a grid. An additional section shows how to use FireDAC components to execute commands from code.
Create a Connection to Snowflake 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.
Snowflake データベースに接続するには、認証に加えて次のプロパティを設定します。
- Url:自身のSnowflake URL、例えばhttps://orgname-myaccount.snowflakecomputing.com。
- Legacy URL を使用する場合:https://myaccount.region.snowflakecomputing.com
- 自身のURL を見つけるには:
- Snowflake UI の左下にある自身の名前をクリックします。
- Account ID にカーソルを合わせます。
- Copy Account URL アイコンをクリックして、アカウントURL をコピーします。
- Database(オプション):本製品によって公開されるテーブルとビューを、特定のSnowflake データベースのものに制限します。
- Schema(オプション):本製品によって公開されるテーブルとビューを、特定のSnowflake データベーススキーマのものに制限します。
Snowflake への認証
本製品は、Snowflake ユーザー認証、フェデレーション認証、およびSSL クライアント認証をサポートしています。認証するには、User とPassword を設定し、AuthScheme プロパティで認証メソッドを選択します。
キーペア
ユーザーアカウントに定義されたプライベートキーを使用してセキュアなトークンを作成することにより、キーペア認証を使用して認証できます。この方法で接続するには、AuthScheme をPRIVATEKEY に設定し、次の値を設定します。
- User:認証に使用するユーザーアカウント。
- PrivateKey:プライベートキーを含む.pem ファイルへのパスなど、ユーザーに使用されるプライベートキー。
- PrivateKeyType:プライベートキーを含むキーストアの種類(PEMKEY_FILE、PFXFILE など)。
- PrivateKeyPassword:指定されたプライベートキーのパスワード。
その他の認証方法は、ヘルプドキュメントの「Snowflake への認証」セクション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 Snowflake.
- In a new VCL Forms application, expand the FireDAC node in the Data Explorer.
- Right-click the ODBC Data Source node in the Data Explorer.
- Click Add New Connection.
- Enter a name for the connection.
- In the FireDAC Connection Editor that appears, set the DataSource property to the name of the ODBC DSN for Snowflake.

Create VCL Applications with Connectivity to Snowflake データ
Follow the procedure below to start querying Snowflake のデータ from a simple VCL application that displays the results of a query in a grid.
-
Drop a TFDConnection component onto the form and set the following properties:
- ConnectionDefName: Select the FireDAC connection to Snowflake.
- Connected: Select True from the menu and, in the dialog that appears, enter your credentials.
-
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, ProductName FROM Products
- Active: Set this property to true.
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.
-
Drop a TDBGrid control onto the form and set the following property:
- DataSource: Select the name of the TDataSource.
- Drop a TFDGUIxWaitCursor onto the form — this is required to avoid a run-time error.

Execute Commands to Snowflake with FireDAC Components
You can use the TFDConnection and TFQuery components to execute queries to Snowflake のデータ. This section provides snowflakespecific examples of executing queries with the TFQuery component.
Connect to Snowflake データ
To connect to the data source, set the Connected property of the TFDConnection component to true. You can set the same properties from code:
FDConnection1->ConnectionDefName = "CData Snowflake ODBC Source";
FDConnection1->Connected = true;
To connect the TFDQuery component to Snowflake のデータ, set the Connection property of the component. When a TFDQuery component is added at design time, its Connection property is automatically set to point to a TFDConnection on the form, as in the application above.
Create Parameterized Queries
To create a parameterized query, use the following syntax below:
FDQuery1->SQL->Text = "select * from Products where id = :Id";
FDQuery1->ParamByName("id")->AsString = "1";
query->Open();
The example above binds a string-type input parameter by name and then opens the dataset that results.
Prepare the Statement
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.
FDQuery1->SQL->Text := "select * from Products where id = :Id";
FDQuery1.ParamByName("id")->AsString = "1";
FDQuery1->Open();
To execute a query that does not return a result set, 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.
FDQ.SQL.Text := "delete from Products where Id = :Id";
FDQuery1->Params->Items[0]->AsString = "x12345";
FDQuery1->ExecSQL();
AnsiString i = FDQuery1->RowsAffected;
Related Articles
Below you can find other articles for using the CData ODBC Driver with RAD Studio, Delphi, and C++ Builder.