The ADO Data Control

Universal Data Access Open Database Connectivity (ODBC) –standard for accessing data in databases OLE-DB –allows access to data in many formats –faster and easier to use than ODBC

OLE-DB Application OLE-DB Provider OLE-DB Provider OLE-DB Provider OLE-DB Provider OLE-DB Provider ODBC Data Access SQL Server OracleExcel ODBC ADO …

ADO, DAO and RDO in Visual Basic In Visual Basic, three data access interfaces are available to you: –ActiveX Data Objects (ADO) –Remote Data Objects (RDO) –Data Access Objects (DAO) Data access technology is constantly evolving, and each of the three interfaces represents a different stage of development for data access technology. The latest is ADO. It features a simpler — yet more flexible — object model than either RDO or DAO. For new projects, you should use ADO as your data access interface.

The ADO Object Model Four main objects: *Connection – the link between the program and the data store *Command – allows you to run commands against the data store *Recordset – contains all the data returned from a specific action on the data store *Stream – allows the manipulation of data held in web resources, such as HTML files

Using the ADO Data Control Add the Microsoft ADO Data Control 6.0 (OLEDB) component to your project. Create an instance of the ADO Data Control on your form. Connect to a database with the ADO Data Control by building a connection string. Set the RecordSource property of the ADO Data Control Create bound controls on your form.

Building a Connection String In the properties window of the ADO Data control’s choose the ConnectionString property. 3 Methods From the property pages, choose Use Connection String and choose Build From the Provider tab in the Data Link Properties dialog box, specify which data provider to use. –use Microsoft Jet 4.0 OLE DB Provider for Access databases –choose Next >> to bring up the Connection tab of the Data Link Properties dialog box

Building a Connection String Three methods –Use a data Data Link File –Use an ODBC Data Source Name –Use a Connection String Back

Building a Connection String From the Connection tab, enter your database name and path (or browse for it) Leave the default log on information Test Connection

Set the RecordSource property of the ADO Data Control In the properties window of the ADO Data control’s choose the RecordSource property. Choose a Command Type –adCmdUnknown –adCmdTable –adCmdText –adCmdStoredProc Select a table or enter an SQL statement

Creating Bound Controls Many different controls that can hold text and graphics can be bound to a field in an ADO Data control. Set the DataSource property of the bound control to the ADO Data Control. Set the DataField property of the bound control to the field you want to display