更新数据库数据的问题！！急急急！！！！

[xivi]

请问我下面的程序那里有问题??为什么会出现“未处理的“System.InvalidOperationException”类型的异常出现在 system.data.dll 中

其他信息：对于不返回任何键列信息的 SelectCommand 不支持 UpdateCommand 的动态 SQL 生成。” 这句错误提示

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim strCnn As String = "server=jet;database=powerscan;uid=psuser;password=psuser;"
Dim strSQL As String = "select storage_name,free_space from ps_storage"
Dim myDS As New DataSet()
Dim myDA As SqlDataAdapter
Dim Con As New SqlConnection(strCnn)
myDA = New SqlDataAdapter(strSQL, Con)

myDA.Fill(myDS, "storage")

myDS.Tables(0).Rows(0).Item("free_space") = "5000"


Dim objBuilder As SqlCommandBuilder

objBuilder = New SqlCommandBuilder(myDA)

myDA.UpdateCommand = objBuilder.GetUpdateCommand()' 这里开始有错
myDA.InsertCommand = objBuilder.GetInsertCommand()
myDA.DeleteCommand = objBuilder.GetDeleteCommand()


myDA.Update(myDS, "storage")


End Sub

[layershow]

你的select 需要选一个主键或者是标识
不然Update 不知道要更新哪条记录