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我有一个 Datagridview，其中填充了来自 SQL Server 的一些数据。这完全没有问题。

每次我在表中插入或更新记录时，我都想对一个表IDENTITY名的列进行 RESEED CarID，但是 IDS 的顺序似乎不好，因为有时会删除记录。

在我的代码中，我使用“SQLCOMMANDBUILDER”来执行插入、更新或删除操作。

我已经尝试了下面的代码，但我抛出了一个异常错误，上面写着“找不到表 0”。

我应该在哪里修？？

//THESE ARE CODE TO RESEED AN IDENTITY COLUMN

Sub ResetIDColumn()
    Try
        Dim querystring As String = "declare @max int " &
                        "Select @max=max([CarID]) FROM [dbo].[Cars]" &
                        "if @max IS NULL SET @max = 0 " &
                        "DBCC CHECKIDENT ('[Cars]', RESEED,@max)"
        ds = New DataSet
        da = New SqlDataAdapter(querystring, con)
        cmdbuilder = New SqlCommandBuilder(da)
        da.Fill(ds)
        DgvCarList.DataSource = ds.Tables(0)

    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

 //CODE TO PUPOLATE DATAGRIDVIEW
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) 
Handles MyBase.Load
    Try
        Dim querystring As String = "SELECT * FROM [dbo].[Cars]"
        ds = New DataSet
        da = New SqlDataAdapter(querystring, con)
        cmdbuilder = New SqlCommandBuilder(da)
        da.Fill(ds)
        DgvCarList.DataSource = ds.Tables(0)

    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

//CODE TO INSERT OR UPDATE DATA

Private Sub btnUpdate_Click(sender As System.Object, e As System.EventArgs) Handles btnUpdate.Click
    ResetIDColumn()
    Try
        da.Update(ds.Tables(0))
        MessageBox.Show("Update was successful!", "Data")
        Loaddata()
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub

//CODE TO LOAD DATA 
Sub Loaddata()
    Dim querystring As String = "SELECT * FROM [dbo].[Cars]"
    ds = New DataSet
    da = New SqlDataAdapter(querystring, con)
    cmdbuilder = New SqlCommandBuilder(da)
    da.Fill(ds)
    DgvCarList.DataSource = ds.Tables(0)
    DgvCarList.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
End Sub
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1 回答 1

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我越努力越努力，最后我发现——；

  1. 您需要创建一个新数据集、Sqlcommandbuilder 和新数据适配器，然后
    从您的表中查询数据（使用 select 语句），同时执行命令以使用“单个查询字符串”重置 id。

  2. 执行两个命令的目的是使所有结果都存储在 SINGLE DATASET 中

  3. 我决定在从表中删除记录后调用这个子。

代码：

// Button click to delete a record
 Try
        If ds.Tables(0).Rows.Count > 0 Then
            Dim rowposition As Integer = DgvCarList.CurrentRow.Index
            Dim rowdelete As DataRow = ds.Tables(0).Rows(rowposition)
            rowdelete.Delete()
            da.Update(ds)
            MessageBox.Show("Delete was success!", "Data")
            Loaddata()
        End If
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try

  // After delete completed Go and reset an identity column 
    ResetIDColumn()


  // code to reset an identity column
 Sub ResetIDColumn()
    Try
        Dim querystring As String = "SELECT * FROM [dbo].[Cars] go " &
                                     "DECLARE @max INT " &
                        "Select @max=max([CarID]) FROM [dbo].[Cars]" &
                        "if @max IS NULL SET @max = 0 " &
                        "DBCC CHECKIDENT ('[Cars]', RESEED,@max)"
        ds = New DataSet
        da = New SqlDataAdapter(querystring, con)
        cmdbuilder = New SqlCommandBuilder(da)
        da.Fill(ds)
        DgvCarList.DataSource = ds.Tables(0)

    Catch ex As Exception
        MessageBox.Show(ex.Message)
    End Try
End Sub


          ...................Thank you all..................................
于 2019-04-07T16:11:44.467 回答