提交新记录前检查记录是否存在

Question

我目前有一个函数，可以在 Access 2010 中使用 SQL 语句将记录插入 table。

Sub btnSubmit_Click()

dim strSQL as string

strSQL="INSERT INTO tblMaster (PeriodID,ClassID,ChildID,SubjectID,LevelID) VALUES (" & cboPeriod & "," & cboClass & "," & cboName & "," & tbSubject1 & "," & cboLevel1 & ")"

CurrentDB.Execute strSQL
End Sub

我首先想做的是检查 'tblMaster' 是否已经有相同的记录。

我该如何实现？

Answer 1

您可以使用另一个 select 语句检查该记录是否存在。

Answer 2

我原以为在最坏的情况下只有几个唯一标识符；以下应该工作。

Sub btnSubmit_Click()
    Dim strSQL as string

    strSQL = "INSERT INTO tblMaster (PeriodID, ClassID, ChildID, SubjectID, LevelID) VALUES (" & _
                cboPeriod & ", " & cboClass & ", " & cboName & ", " & tbSubject1 & ", " & cboLevel1 & ")"

    If DCount("*", "tblMaster", "PeriodID = " & cboPeriod & " AND " & _
                                "ClassID = " & cboClass & " AND " & _
                                "ChildID = " & cboName & " AND " & _
                                "SubjectID = " & tbSubject1 & " AND " & _
                                "LevelID = " & cboLevel1) = 0 Then
        CurrentDB.Execute strSQL
    Else
        MsgBox "A Record already exists for this information.", vbOKOnly, "No Records Added."
    End If
End Sub

提交新记录前检查记录是否存在

Check if record exists before submitting new

sql

ms-access

vba