主题：引用自动更新

If e.DataCol.Name = "产品编号" Then Dim acmd As New SQLCommand Dim adt As DataTable Dim adr As DataRow = e.DataRow acmd.CommandText = "SELECT 成本价 From {产品表} Where [产品编号] = '" & adr("产品编号") & "'Order By 日期 Desc" adt = acmd.ExecuteReader If adt.DataRows.Count > 0 Then adr("单价") = adt.DataRows(0)("成本价") Else adr("单价") = Nothing End If End If If e.DataCol.Name = "成本价" Then DataTables("产品表").DataCols("单价").RaiseDataColChanged() End If   用上述代码执行效力非常低 求助，解决方案或代码优化 谢谢！

 
If e.DataCol.Name = "产品编号" Then
Dim acmd As New SQLCommand
'Dim adt As DataTable
Dim adt As Double
Dim adr As DataRow = e.DataRow
acmd.CommandText = "SELECT 成本价 From {产品表} Where [产品编号] = '" & adr("产品编号") & "'Order By 日期 Desc"
'adt = acmd.ExecuteReader
adt = acmd.ExecuteScalar()
'If adt.DataRows.Count > 0 Then
If adt <> 0 Then
'adr("单价") = adt.DataRows(0)("成本价")
adr("单价") = adt
Else
adr("单价") = Nothing
End If
End If

If e.DataCol.Name = "成本价" Then
DataTables("产品表").DataCols("单价").RaiseDataColChanged("[产品编号] = '" & e.DataRow("产品编号") & "'")
End If

 还有就是，最好说一下你的用意。

acmd.CommandText ="SELECT top 1 成本价 From {产品表} Where [产品编号] = '" & adr("产品编号") & "'Order By 日期 Desc"

dim int as integer =  acmd.ExecuteScalar

 

非常感谢各位的帮助，现在快了很多