通过

Workspace.DefaultCursorDriver 属性 (DAO)

适用于：Access 2013、Office 2013

语法

表达式 。DefaultCursorDriver

表达式 一个表示 Workspace 对象的变量。

备注

可以将该设置值或返回值设置为 CursorDriverEnum 常量之一。

该属性设置仅影响在设置了该属性后建立的连接。 更改 DefaultCursorDriver 属性对现有的连接没有影响。

示例

以下示例使用 NextRecordset 方法查看 SELECT 复合查询中的数据。 在执行此类查询时， DefaultCursorDriver 属性必须设置为 dbUseODBCCursor。 即使部分或全部 SELECT 语句返回零记录， NextRecordset 方法也会返回 True；仅当检查了所有单个 SQL 子句后，它才返回 False。

    Sub NextRecordsetX() 
     
     Dim wrkODBC As Workspace 
     Dim conPubs As Connection 
     Dim rstTemp As Recordset 
     Dim intCount As Integer 
     Dim booNext As Boolean 
     
     ' Create ODBCDirect Workspace object and open Connection 
     ' object. The DefaultCursorDriver setting is required 
     ' when using compound SQL statements. 
     Set wrkODBC = CreateWorkspace("", _ 
     "admin", "", dbUseODBC) 
     wrkODBC.DefaultCursorDriver = dbUseODBCCursor 
     
     ' Note: The DSN referenced below must be set to 
     ' use Microsoft Windows NT Authentication Mode to 
     ' authorize user access to the Microsoft SQL Server. 
     Set conPubs = wrkODBC.OpenConnection("Publishers", , , _ 
     "ODBC;DATABASE=pubs;DSN=Publishers") 
     
     ' Construct compound SELECT statement. 
     Set rstTemp = conPubs.OpenRecordset("SELECT * " & _ 
     "FROM authors; " & _ 
     "SELECT * FROM stores; " & _ 
     "SELECT * FROM jobs") 
     
     ' Try printing results from each of the three SELECT 
     ' statements. 
     booNext = True 
     intCount = 1 
     With rstTemp 
     Do While booNext 
     Debug.Print "Contents of recordset #" & intCount 
     Do While Not .EOF 
     Debug.Print , .Fields(0), .Fields(1) 
     .MoveNext 
     Loop 
     booNext = .NextRecordset 
     Debug.Print " rstTemp.NextRecordset = " & _ 
     booNext 
     intCount = intCount + 1 
     Loop 
     End With 
     
     rstTemp.Close 
     conPubs.Close 
     wrkODBC.Close 
     
    End Sub

完成同一任务的另一种方法是创建一个包含 SQL 复合语句的预备语句。 QueryDef 对象的 CacheSize 属性必须设置为 1， Recordset 对象必须为仅向前类型，并且是只读的。

Sub NextRecordsetX2() 
 
 Dim wrkODBC As Workspace 
 Dim conPubs As Connection 
 Dim qdfTemp As QueryDef 
 Dim rstTemp As Recordset 
 Dim intCount As Integer 
 Dim booNext As Boolean 
 
 ' Create ODBCDirect Workspace object and open Connection 
 ' object. The DefaultCursorDriver setting is required 
 ' when using compound SQL statements. 
 Set wrkODBC = CreateWorkspace("", _ 
 "admin", "", dbUseODBC) 
 wrkODBC.DefaultCursorDriver = dbUseODBCCursor 
 
 ' Note: The DSN referenced below must be set to 
 ' use Microsoft Windows NT Authentication Mode to 
 ' authorize user access to the Microsoft SQL Server. 
 Set conPubs = wrkODBC.OpenConnection("Publishers", , , _ 
 "ODBC;DATABASE=pubs;DSN=Publishers") 
 
 ' Create a temporary stored procedure with a compound 
 ' SELECT statement. 
 Set qdfTemp = conPubs.CreateQueryDef("", _ 
 "SELECT * FROM authors; " & _ 
 "SELECT * FROM stores; " & _ 
 "SELECT * FROM jobs") 
 ' Set CacheSize and open Recordset object with arguments 
 ' that will allow access to multiple recordsets. 
 qdfTemp.CacheSize = 1 
 Set rstTemp = qdfTemp.OpenRecordset(dbOpenForwardOnly, _ 
 dbReadOnly) 
 
 ' Try printing results from each of the three SELECT 
 ' statements. 
 booNext = True 
 intCount = 1 
 With rstTemp 
 Do While booNext 
 Debug.Print "Contents of recordset #" & intCount 
 Do While Not .EOF 
 Debug.Print , .Fields(0), .Fields(1) 
 .MoveNext 
 Loop 
 booNext = .NextRecordset 
 Debug.Print " rstTemp.NextRecordset = " & _ 
 booNext 
 intCount = intCount + 1 
 Loop 
 End With 
 
 rstTemp.Close 
 qdfTemp.Close 
 conPubs.Close 
 wrkODBC.Close 
 
End Sub

以下示例使用 RecordStatus 和 DefaultCursorDriver 属性演示如何在批更新中跟踪对本地 Recordset 的更改。 若要使该过程运行，需要使用 RecordStatusOutput 函数。

Sub RecordStatusX() 
 
 Dim wrkMain As Workspace 
 Dim conMain As Connection 
 Dim rstTemp As Recordset 
 
 Set wrkMain = CreateWorkspace("ODBCWorkspace", _ 
 "admin", "", dbUseODBC) 
 ' This DefaultCursorDriver setting is required for 
 ' batch updating. 
 wrkMain.DefaultCursorDriver = dbUseClientBatchCursor 
 
 ' Note: The DSN referenced below must be configured to 
 ' use Microsoft Windows NT Authentication Mode to 
 ' authorize user access to the Microsoft SQL Server. 
 Set conMain = wrkMain.OpenConnection("Publishers", _ 
 dbDriverNoPrompt, False, _ 
 "ODBC;DATABASE=pubs;DSN=Publishers") 
 
 ' The following locking argument is required for 
 ' batch updating. 
 Set rstTemp = conMain.OpenRecordset( _ 
 "SELECT * FROM authors", dbOpenDynaset, 0, _ 
 dbOptimisticBatch) 
 
 With rstTemp 
 .MoveFirst 
 Debug.Print "Original record: " & !au_lname 
 Debug.Print , RecordStatusOutput2(.RecordStatus) 
 
 .Edit 
 !au_lname = "Bowen" 
 .Update 
 Debug.Print "Edited record: " & !au_lname 
 Debug.Print , RecordStatusOutput2(.RecordStatus) 
 
 .AddNew 
 !au_lname = "NewName" 
 .Update 
 Debug.Print "New record: " & !au_lname 
 Debug.Print , RecordStatusOutput2(.RecordStatus) 
 
 .Delete 
 Debug.Print "Deleted record: " & !au_lname 
 Debug.Print , RecordStatusOutput2(.RecordStatus) 
 
 ' Close the local recordset without updating the 
 ' data on the server. 
 .Close 
 End With 
 
 conMain.Close 
 wrkMain.Close 
 
End Sub 
 
Function RecordStatusOutput(lngTemp As Long) As String 
 
 Dim strTemp As String 
 
 strTemp = "" 
 
 ' Construct an output string based on the RecordStatus 
 ' value. 
If lngTemp = dbRecordUnmodified Then _ 
 strTemp = "[dbRecordUnmodified]" 
 If lngTemp = dbRecordModified Then _ 
 strTemp = "[dbRecordModified]" 
 If lngTemp = dbRecordNew Then _ 
 strTemp = "[dbRecordNew]" 
 If lngTemp = dbRecordDeleted Then _ 
 strTemp = "[dbRecordDeleted]" 
 If lngTemp = dbRecordDBDeleted Then _ 
 strTemp = "[dbRecordDBDeleted]" 
 
 RecordStatusOutput = strTemp 
 
End Function
  • Last updated on