Seek Method and Index Property Example (VB)
This example uses the Recordset object's Seek method and Index property in conjunction with a given Employee ID, to locate the employee's name in the Employees table of the Nwind.mdb database.
'BeginSeekVB
Public Sub SeekX()
On Error GoTo ErrorHandler
' To integrate this code replace the data source
' in the connection string
'recordset and connection variables
Dim rstEmployees As ADODB.Recordset
Dim Cnxn As ADODB.Connection
Dim strCnxn As String
Dim strSQLEmployees As String
Dim strID As String
Dim strPrompt As String
strPrompt = "Enter an EmployeeID (e.g., 1 to 9)"
' Open connection
Set Cnxn = New ADODB.Connection
strCnxn = "Provider='Microsoft.Jet.OLEDB.4.0';" & _
"Data Source='C:\Program Files\Microsoft Office XP\Office10\Samples\northwind.mdb';"
Cnxn.Open strCnxn
' open recordset server-side for indexing
Set rstEmployees = New ADODB.Recordset
rstEmployees.CursorLocation = adUseServer
strSQLEmployees = "employees"
rstEmployees.Open strSQLEmployees, strCnxn, adOpenKeyset, adLockReadOnly, adCmdTableDirect
' Does this provider support Seek and Index?
If rstEmployees.Supports(adIndex) And rstEmployees.Supports(adSeek) Then
rstEmployees.Index = "PrimaryKey"
' Display all the employees
rstEmployees.MoveFirst
Do While rstEmployees.EOF = False
Debug.Print rstEmployees!EmployeeId; ": "; rstEmployees!FirstName; " "; _
rstEmployees!LastName
rstEmployees.MoveNext
Loop
' Prompt the user for an EmployeeID between 1 and 9
rstEmployees.MoveFirst
Do
strID = LCase(Trim(InputBox(strPrompt, "Seek Example")))
' Quit if strID is a zero-length string (CANCEL, null, etc.)
If Len(strID) = 0 Then Exit Do
If Len(strID) = 1 And strID >= "1" And strID <= "9" Then
rstEmployees.Seek Array(strID), adSeekFirstEQ
If rstEmployees.EOF Then
Debug.Print "Employee not found.", , "Seek Example"
MsgBox "Employee not found."
Else
Debug.Print strID; ": Employee='"; rstEmployees!FirstName; " "; _
rstEmployees!LastName; "'"
MsgBox "EmployeeID is: " + strID + "; Employee Name is: '" + rstEmployees!FirstName + " " + _
rstEmployees!LastName + "'", , "Seek Example"
End If
Else
MsgBox "You entered a wrong EmployeeID, please enter a new ID."
End If
Loop
End If
' clean up
rstEmployees.Close
Cnxn.Close
Set rstEmployees = Nothing
Set Cnxn = Nothing
Exit Sub
ErrorHandler:
' clean up
If Not rstEmployees Is Nothing Then
If rstEmployees.State = adStateOpen Then rstEmployees.Close
End If
Set rstEmployees = Nothing
If Not Cnxn Is Nothing Then
If Cnxn.State = adStateOpen Then Cnxn.Close
End If
Set Cnxn = Nothing
If Err <> 0 Then
MsgBox Err.Source & "-->" & Err.Description, , "Error"
End If
End Sub
'EndSeekVB