MS Access 记录数始终为 1，即使没有记录

Posted 2023-03-27

【中文标题】MS Access 记录数始终为 1，即使没有记录

【英文标题】：MS Access recordcount is always 1 even with no record

【发布时间】：2021-10-14 04:59:00

【问题描述】：

我正在使用 MS Access 2010。我正在尝试搜索表并根据名字和姓氏确定记录是否存在，如果记录存在则更新记录，如果不存在，则插入新记录记录。我没有收到任何错误，但即使我输入了我知道表中不存在的名称，我的记录数也始终为 1。

    Private Sub txtSearchFirstName_Exit(Cancel As Integer)
    Dim strSQL As String
    Dim db As Database
    Dim rs As DAO.Recordset
    Dim recordCount As Long

    Set db = CurrentDb
    Set rs = Nothing

    Stop

    ''Check if a keyword entered or not
    If IsNull(Me.txtSearchlastName) = "" Then
    MsgBox "Please type in your search keyword.", vbOKOnly, "Keyword Needed"

Else

    strSQL = "SELECT COUNT(*) " & _
    "FROM tblBobbettesMarketBulletin_CustNum " & _
    "WHERE tblBobbettesMarketBulletin_CustNum.Last = " & Chr(34) & txtSearchlastName & Chr(34) & _
    " AND tblBobbettesMarketBulletin_CustNum.First = " & Chr(34) & txtSearchFirstName & Chr(34)
    Debug.Print strSQL
   

    Set rs = db.OpenRecordset(strSQL, dbOpenDynaset)
    
    If (rs.BOF And rs.EOF) Then
            recordCount = 0
        Else
            rs.MoveLast
            recordCount = rs.recordCount
    
    End If
    If recordCount > 0 Then MsgBox ("Record exists")

    If recordCount = 0 Then MsgBox ("Record does not exist")
    
     rs.Close

    Set rs = Nothing
    

    End If
    End Sub     

【问题讨论】：

记录集包含一条记录，其中一个字段向您显示与您的WHERE 条件匹配的tblBobbettesMarketBulletin_CustNum 记录中的COUNT。如果没有匹配项，则记录集将包含一条在COUNT 字段中为零的记录。在打开记录集后将Debug.Print rs.Fields(0).Value 添加到您的代码中 --- 也许这将有助于澄清情况。

复习，特别是古斯塔夫回答***.com/questions/6199417/upserting-in-ms-access

谢谢，这很有帮助

谨防 SQL 注入。如果有人输入 Thomas “Tommy”的名字，查询将失败。

【参考方案1】：

@HansUp 完美地描述了您的问题。

如果您想简化代码并使用此功能，请为您的 Count(*) 分配一个字段名称，然后一步查询并使用其值

strSQL = "SELECT COUNT(*) AS NumFound " & _
"FROM tblBobbettesMarketBulletin_CustNum " & _
"WHERE tblBobbettesMarketBulletin_CustNum.Last = " & Chr(34) & txtSearchlastName & Chr(34) & _
" AND tblBobbettesMarketBulletin_CustNum.First = " & Chr(34) & txtSearchFirstName & Chr(34)
Debug.Print strSQL
   

Set rs = db.OpenRecordset(strSQL, dbOpenDynaset)

MsgBox ("Found " & rs!NumFound & " Record(s)")