1. Using ADO Programmatically The Connection Object, Command Object, and Recordset Object

2. Using ADO Programmatically To perform ADO operations without the aid of the ADO Data control: –Establish a connection to a data source –Define a command –Execute the command –Commands may or may not return records. If they do, create a recordset. –Manipulate the records in the recordset as desired.

3. ADO Object Hierarchy A Connection object represents an open connection to a data source. Connection Command Recordset Errors

4. Connection Object Properties and Methods Properties: –ConnectionString –ConnectionTimeout –CommandTimeout –CursorLocation –Mode –Provider Methods –Open –Close

5. ConstantDescription adModeUnknownDefault. Indicates that the permissions have not yet been set or cannot be determined. adModeReadIndicates read-only permissions. adModeWriteIndicates write-only permissions. adModeReadWriteIndicates read/write permissions. adModeShareDenyReadPrevents others from opening connection with read permissions. adModeShareDenyWritePrevents others from opening connection with write permissions. adModeShareExclusivePrevents others from opening connection. adModeShareDenyNonePrevents others from opening connection with any permissions. Mode Property Values

6. Building the Connection Object Programmatically Create an instance of an ADO Connection object Set the necessary arguments for the ConnectionString property of the Connection object. Call the Open method of the Connection object.

7. Creating an Instance of the ADO Object You must create an instance of a particular ADO object before you can use it. Example: Dim conMagnet As New ADODB.Connection

8. ConnectionString Property The ConnectionString property is a string with which you specify a data source. It defines connection information in the form of argument = value pairs separated by semicolons (;). ADO supports the following arguments: –Provider –Data Source –User ID and Password –File Name –Remote Provider and Remote Server

9. Private Sub Form_Load() ' Declare the Connection object. Dim conMagnet As New ADODB.Connection ' Define the properties for the Connection object conMagnet.Mode = adModeShareDenyNone conMagnet.CursorLocation = adUseClient conMagnet.Provider = "Microsoft.Jet.OLEDB.4.0" conMagnet.ConnectionString = "Data Source=A:\Magnet.mdb“ ' Call the Open Method of the Connection object conMagnet.Open End Sub

10. The Command Object Properties –ActiveConnection –CommandType adCmdText, adCmdTable, adCmdStoredProcedure –CommandText Methods –Execute –Cancel

11. Private Sub Form_Load() ' Declare the Connection and Command objects. Dim conMagnet As New ADODB.Connection Dim cmdMagnet As New ADODB.Command ' Define the properties for the Connection object ' then open the connection. conMagnet.Mode = adModeShareDenyNone conMagnet.CursorLocation = adUseClient conMagnet.Provider = "Microsoft.Jet.OLEDB.4.0" conMagnet.ConnectionString = "Data Source=A:\Magnet.mdb" conMagnet.Open ' Define the propeties for the Command object. Set cmdMagnet.ActiveConnection = conMagnet cmdMagnet.CommandType = adCmdTable cmdMagnet.CommandText = "tblOrderMaster“ End Sub

12. ' Module level variable to store a reference to the form's recordset. Private rstCurrent As New ADODB.Recordset Private Sub Form_Load() Dim conMagnet As New ADODB.Connection Dim cmdMagnet As New ADODB.Command conMagnet.Mode = adModeShareDenyNone conMagnet.CursorLocation = adUseClient conMagnet.Provider = "Microsoft.Jet.OLEDB.4.0" conMagnet.ConnectionString = "Data Source=A:\Magnet.mdb" conMagnet.Open Set cmdMagnet.ActiveConnection = conMagnet cmdMagnet.CommandType = adCmdTable cmdMagnet.CommandText = "tblOrderMaster“ rstCurrent.Open cmdMagnet End Sub

13. Private Sub LoadCurrentRecord() txtOrderID.Text = rstCurrent.Fields("fldOrderID") txtCustomerID.Text = rstCurrent.Fields("fldCustomerID") txtOrderDate.Text = rstCurrent.Fields("fldOrderDate") txtOrderCost.Text = rstCurrent.Fields("fldOrderCost") txtOrderSales.Text = rstCurrent.Fields("fldOrderSales") lblCurrentRecord.Caption = rstCurrent.AbsolutePosition lblRecordCount.Caption = rstCurrent.RecordCount End Sub

14. Looping Through Records in a Recordset Do Until rstCurrent.EOF cboMemID.AddItem rstCurrent("Member ID") rstCurrent.MoveNext Loop