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TA贡献1805条经验 获得超10个赞
找到了一个很好的代码,并带有解释每个语句的注释。在-accessallinone找到代码
Sub DAOLooping()
On Error GoTo ErrorHandler
Dim strSQL As String
Dim rs As DAO.Recordset
strSQL = "tblTeachers"
'For the purposes of this post, we are simply going to make
'strSQL equal to tblTeachers.
'You could use a full SELECT statement such as:
'SELECT * FROM tblTeachers (this would produce the same result in fact).
'You could also add a Where clause to filter which records are returned:
'SELECT * FROM tblTeachers Where ZIPPostal = '98052'
' (this would return 5 records)
Set rs = CurrentDb.OpenRecordset(strSQL)
'This line of code instantiates the recordset object!!!
'In English, this means that we have opened up a recordset
'and can access its values using the rs variable.
With rs
If Not .BOF And Not .EOF Then
'We don’t know if the recordset has any records,
'so we use this line of code to check. If there are no records
'we won’t execute any code in the if..end if statement.
.MoveLast
.MoveFirst
'It is not necessary to move to the last record and then back
'to the first one but it is good practice to do so.
While (Not .EOF)
'With this code, we are using a while loop to loop
'through the records. If we reach the end of the recordset, .EOF
'will return true and we will exit the while loop.
Debug.Print rs.Fields("teacherID") & " " & rs.Fields("FirstName")
'prints info from fields to the immediate window
.MoveNext
'We need to ensure that we use .MoveNext,
'otherwise we will be stuck in a loop forever…
'(or at least until you press CTRL+Break)
Wend
End If
.close
'Make sure you close the recordset...
End With
ExitSub:
Set rs = Nothing
'..and set it to nothing
Exit Sub
ErrorHandler:
Resume ExitSub
End Sub
记录集在遍历数据时具有两个重要的属性,EOF(文件末尾)和BOF(文件开始)。记录集就像表一样,当您遍历一个表时,实际上是按顺序从一个记录移到另一个记录。当您在记录中移动时,EOF属性设置为false,但在尝试通过最后一条记录后,EOF属性变为true。反之,BOF属性的工作原理与此相反。
这些属性使我们知道何时达到记录集的限制。
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