更新，向数据表VB.Net添加行

Question

我努力解决我的问题，这就是我要做的事情：

• 我有一个XML文件，我使用ReadXML加载到数据集（“ds”）中，几个表填充到数据集中，我关注的是（“SalesReceiptRet”），我将其称为源表。
• 我在MS Access数据库中有另一个表，我将其加载到相同的表中 使用OleDBAdapter.Fill的数据集，到名为（“dtTarget”）的数据表中，适配器的名称是（“dbAdapter”）。

我想查看源表中的所有记录，查找名为（“TxnID”）的字段以在目标表中查找记录。如果它不存在，请添加它，如果它确实进行了另一次验证并使用源的行覆盖/更新它。

这是代码：

Private Sub btnTest_Click(sender As Object, e As EventArgs) Handles btnTest.Click
    'Initialize command builder
    Dim dbCommandBuilder As New OleDb.OleDbCommandBuilder(dbAdapter)

    'Set the primary keys
    ds.Tables("dtTarget").PrimaryKey = New DataColumn() {ds.Tables("dtTarget").Columns("TxnID")}

    'Find rows
    Dim dr As DataRow
    Dim lookupRow As DataRow

    For Each dr In ds.Tables("SalesReceiptRet").Rows

        lookupRow = ds.Tables("dtTarget").Rows.Find(dr.Item(0))
        'If the a row with a similar TxnID exists, do the following validation
        If Not (lookupRow Is Nothing) Then
            If lookupRow.Item(8).ToString <> "Regular" Then
                'do something here to overwrite/update the matching row
            End If
        Else
            'If the row does not exist, import it
            ds.Tables("dtTarget").ImportRow(dr)
        End If

    Next

    'Update Access
    dbAdapter.Update(ds, "dtTarget")
    dbConnection.Close()


End Sub

也许我需要提一下两个表都有精确的列名，除了Access“dtTarget”还有其他的，这似乎不会导致问题，至少导入行。

有什么想法吗？

Answer 1

这应该让你开始，

有关Access和适配器上的插入/更新的更多帮助，请参阅此链接http://social.msdn.microsoft.com/Forums/en-US/adodotnetdataset/thread/958e6d51-725a-4649-8fc0-79a831f8f37e

Dim connStr As String = "Provider=SQLNCLI10;Server=(local);Database=MyNewTest;Uid=user; Pwd=******;"
Dim selectCmd As String = "select * from IdentityTest"
Dim dbAdapter As New OleDb.OleDbDataAdapter(selectCmd, connStr)
dbAdapter.AcceptChangesDuringUpdate = True

'code here to fille up your adapter
'build the insert and update comand on the adapter
Dim InsertCommans As New OleDb.OleDbCommand("INSERT INTO <table> (field1,field2,field3,field4) Values (@val1,@val2,@val3,@val4)")
Dim UpdateCommans As New OleDb.OleDbCommand("UPDATE <table> SET <field> = @Value WHERE <field> = @TxnID")

'Set the primary keys
Dim ds As DataSet
ds.Tables("dtTarget").PrimaryKey = New DataColumn() {ds.Tables("dtTarget").Columns("TxnID")}

'assign our datatables
Dim oDtSource As DataTable = ds.Tables("SalesReceiptRet")
Dim oDtTarget As DataTable : dbAdapter.Fill(oDtTarget)

'for each TxnID in our source table
For Each dr As DataRow In oDtSource.Rows

'get the rows in the target that match to the current source table row taxnid [colname] = TxnID
Dim oRowsInTarget As DataRow() = oDtTarget.Select("[" & oDtTarget.Columns(0).ColumnName & "] = " & dr("TxnID"))
'if there is a match (assuming there will only be one) and the column 8 contents (this is column 9 in reality)
'dowes not equal "Regular" then proceed to run the ole adapter update statement else insert
If oRowsInTarget.Count > 0 AndAlso Not oRowsInTarget(0)(8).ToString <> "Regular" Then
    'perform our update
    'you have thematching TxnId in dr("TxnID")
    'I think you can configure an insert and update statment on the Ole adapter connected to access
    'EXEC UPDATE ON THE ADAPTER
ElseIf oRowsInTarget.Count > 0 Then
    'EXEC INSERT ON THE ADAPTER
End If
Next