ADOCtl.Exe Demonstrates Active Documents, RDS and ADO (197861)

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ADOCtl.exe contains the following file attributes:

   FileName                  Size
   ---------------------------------
   Readme.txt                 5KB
   Rdssimple.scx              4KB
   Rdssimple.sct              9KB
   Rdssimple.pjx              2KB
   Rdssimple.pjt              4KB
   Rdssimple.app             59KB
   Activedoc.vcx              2KB
   Activedoc.vct              2KB
   Adocontrols.vcx            4KB
   Adocontrols.vct           39KB
   Adosimple.sct              3KB
   Adosimple.scx              3KB
				

Though the controls can be used with plain ADO data, the purpose of the controls is to allow data access using Active Documents and Remote Data Services (RDS). The following controls are included in the Adocontrols.vcx file:

   ADOCheckBox
   ADOComboBox
   ADODataControl
   ADOEditBox
   ADOGrid
   ADOLabel
   ADOListBox
   ADOOptionButton
   ADOOptionGroup
   ADOSpinner
   ADOTextBox
   DataControl (base class for ADODataControl and RDSDataControl)
   RDSDataControl
				

The ADO controls need either a Remote Data Service (RDS) Data Control or an ADO Data Control for their data source. To connect a RDS Data Control to a server, set the following properties:

• Server - Server name, usually in the format of http://MyServer
• Connect - String used to connect to the server, such as "DSN=MyDSN"
• SQL - SQL Select statement.

Once the properties are set, call the BindControls method of the data control to bind the ADO controls to the data control. You can now use the controls as if they are normal Visual FoxPro controls.

To send updates to the server, call the data control's UpdateRecordset method. To cancel changes, call the data control's RefreshRecordset. This has the effect of canceling changes since the RefreshRecordset method requeries the server and refreshes the controls with data that is unchanged.

The ADO Data Control works in a manner similar to the RDS Data Control. The main difference is the properties that must be set:

• ConnectionString - Character string used to connect to the server.
• SQL - SQL Select statement.

For instance, to connect to a SQL Server, the ConnectionString property might be as follows:

   Provider=SQLOLEDB;Data Source=MySQLServer;Initial Catalog=pubs;User
   ID=John;Password=password
				

After setting these properties, call the data control's BindControls method to populate the ADO controls on the form.

Once a data control is added to the form, you can now add ADO controls to the form. The following two custom properties need to be set in order to bind the control to a data control:

• DataControl - Name of the data control to bind to.
• DataControlField - Field of the data control to bind to.

Note that the DataControl and DataControlField properties are similar to the control's ControlSource property. In fact, do not change the control's ControlSource property, as the data control's BindControls method will change the ControlSource based on the DataControl and DataControlField properties.

The Rdssimple.pjx file is a sample Active Document project that demonstrates using the ADO controls for Internet data access. To use the application, create a system data source name (DSN) on the Internet Information Server that points to a SQL Server. Set the database to the Pubs sample database.

Run the Rdssimple.app file either by typing "DO rdssimple.app" in the Command window or by selecting Tools from the main menu, then clicking Run Active Document and selecting Rdssimple.app. Enter the server name and connect string in the appropriate text boxes. The server name will be in the format "http://MyServer" (without the quotes). The connect string will be in the format "dsn=MyDSN;uid=John;password=password;database=pubs" (without the quotes). For the SQL statement, enter "select * from authors", then click the Run button. If the server name, connect string and SQL statement are correct, the ADO controls will be populated with data.

If no SQL Server is available, it is a trivial task to change the DataControl and DataControlField properties as needed to access a different type of data.

The Adosimple.scx file is a sample form demonstrating usage of the ADODatacontrol. To use the form, enter a connection string (such as "provider = sqloledb;data source=MyServer;initial catalog=pubs;user id=John;password=password", without the quotes) and a SQL statement. Click Run and the ADO grid populates with data from the server.