并发冲突问题－－－急急急----加加加

[boys]

vb.net窗体的DataGrid中
Dim sqlDA = New SqlCommandBuilder(DA_A) 'DA_HeTong-SqlDataAdapter
DA_A.Update(DataTable1)


我的表中有ID索引
有时候就没问题，有时候就会出现并发冲突（只有一个用户用），
出现问题后显示
并发冲突，Updatecommand影响0个记录！
然后DataGrid记录前出现红色的“！”号

很郁闷，请高手指教!

[The123]

DA_A.Update(DataTable1.Select(Nothing, Nothing, DataViewRowState.Deleted))
DA_A.Update(DataTable1.Select(Nothing, Nothing, DataViewRowState.ModifiedCurrent))
DA_A.Update(DataTable1.Select(Nothing, Nothing, DataViewRowState.Added))

[fuzhenyu999999]

是否在改变主键值时使用了相同值

[swiminfish_9999]

我也遇到过同样的问题,不过一般是由于两个用户同时对数据进行超作引起的,你看看你打开数据源使用后有没有关闭连接 conn.close . 不排除这种可能.

[bitsbird]

DataSet.AcceptChanges()

[3tzjq]

使用事务处理吧！也有可能是你的Update的CommandText有问题(Where 后面部分)。

[yingshis]

up

[myhgo]

ms-help://MS.VSCC.2003/MS.MSDNQTR.2003FEB.2052/vbcon/html/vbwlkhandlingconcurrencyexception.htm

[TonyTonyQ]

用事务处理来解决，很简单的问题。使用.net的SqlTransaction类来实现
下列範例會建立 SqlConnection 和 SqlTransaction 。它也說明如何使用 BeginTransaction 、 Commit 和 Rollback 方法。

Public Sub RunSqlTransaction(myConnString As String)
Dim myConnection As New SqlConnection(myConnString)
myConnection.Open()

Dim myCommand As SqlCommand = myConnection.CreateCommand()
Dim myTrans As SqlTransaction

' Start a local transaction
myTrans = myConnection.BeginTransaction()
' Must assign both transaction object and connection
' to Command object for a pending local transaction
myCommand.Connection = myConnection
myCommand.Transaction = myTrans

Try
myCommand.CommandText = "Insert into Region (RegionID, RegionDescription) VALUES (100, 'Description')"
myCommand.ExecuteNonQuery()
myCommand.CommandText = "Insert into Region (RegionID, RegionDescription) VALUES (101, 'Description')"
myCommand.ExecuteNonQuery()
myTrans.Commit()
Console.WriteLine("Both records are written to database.")
Catch e As Exception
Try
myTrans.Rollback()
Catch ex As SqlException
If Not myTrans.Connection Is Nothing Then
Console.WriteLine("An exception of type " & ex.GetType().ToString() & _
" was encountered while attempting to roll back the transaction.")
End If
End Try

Console.WriteLine("An exception of type " & e.GetType().ToString() & _
"was encountered while inserting the data.")
Console.WriteLine("Neither record was written to database.")
Finally
myConnection.Close()
End Try
End Sub 'RunSqlTransaction

[TonyTonyQ]

如果只有一个用户用的时候就有问题，并且保证你的程序同一时间只有一个线程访问数据库的话，那就可能是你SQL语句上的问题了，要仔细检查了。

[kissnono]

这个可能是你对数据集的操作有误.
例如:先添加一条记录,然后再把这条记录删除,就会出现这种错误.