如何在VBA DAO记录集中检查null？

Sub CheckNullValue()
    Dim db As DAO.Database
    Dim rs As DAO.Recordset
    Dim fieldName As String
    Dim fieldValue As Variant

    ' 打开数据库和记录集
    Set db = CurrentDb()
    Set rs = db.OpenRecordset("SELECT * FROM YourTableName")

    ' 假设 fieldName 是要检查的字段名称
    fieldName = "YourFieldName"

    ' 遍历记录集
    While Not rs.EOF
        ' 获取字段值
        fieldValue = rs(fieldName)

        ' 检查字段值是否为 null
        If IsNull(fieldValue) Then
            Debug.Print "The field " & fieldName & " is null."
        Else
            Debug.Print "The field " & fieldName & " is not null. The value is: " & fieldValue
        End If

        ' 移动到下一条记录
        rs.MoveNext
    Wend

    ' 关闭记录集和数据库
    rs.Close
    db.Close
End Sub