GetRows 方法示例 (VB)

此示例使用 GetRows 方法从 Recordset 中检索指定数量的行,并使用结果数据填充数组。 在以下两种情况下,GetRows 方法将返回少于所需的行数:已到达 EOF,或者 GetRows 尝试检索已被其他用户删除的记录。 仅当出现第二种情况时,该函数才返回 False。 此过程需要 GetRowsOK 函数才能运行。

'BeginGetRowsVB  
  
    'To integrate this code  
    'replace the data source and initial catalog values  
    'in the connection string  
  
Public Sub Main()  
    On Error GoTo ErrorHandler  
  
     ' connection and recordset variables  
    Dim rstEmployees As ADODB.Recordset  
    Dim Cnxn As ADODB.Connection  
    Dim strSQLEmployees As String  
    Dim strCnxn As String  
    ' array variable  
    Dim arrEmployees As Variant  
    ' detail variables  
    Dim strMessage As String  
    Dim intRows As Integer  
    Dim intRecord As Integer  
  
    ' open connection  
    Set Cnxn = New ADODB.Connection  
    strCnxn = "Provider='sqloledb';Data Source='MySqlServer';" & _  
        "Initial Catalog='Pubs';Integrated Security='SSPI';"  
    Cnxn.Open strCnxn  
  
    ' open recordset client-side to enable RecordCount  
    Set rstEmployees = New ADODB.Recordset  
    strSQLEmployees = "SELECT fName, lName, hire_date FROM Employee ORDER BY lName"  
    rstEmployees.Open strSQLEmployees, Cnxn, adOpenStatic, adLockReadOnly, adCmdText  
  
    ' get user input for number of rows  
    Do  
        strMessage = "Enter number of rows to retrieve:"  
        intRows = Val(InputBox(strMessage))  
  
          ' if bad user input exit the loop  
        If intRows <= 0 Then  
            MsgBox "Please enter a positive number", vbOKOnly, "Not less than zero!"  
        ' if number of requested records is over the total  
        ElseIf intRows > rstEmployees.RecordCount Then  
            MsgBox "Not enough records in Recordset to retrieve " & intRows & " rows.", _  
            vbOKOnly, "Over the available total"  
        Else  
            Exit Do  
        End If  
    Loop  
  
      ' else put the data in an array and print  
    arrEmployees = rstEmployees.GetRows(intRows)  
  
    Dim x As Integer, y As Integer  
  
    For x = 0 To intRows - 1  
        For y = 0 To 2  
            Debug.Print arrEmployees(y, x) & " ";  
        Next y  
        Debug.Print vbCrLf  
    Next x  
  
    ' 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  
'EndGetRowsVB  

另请参阅

GetRows 方法 (ADO)
记录集对象 (ADO)