主题：为何一直出错b.Groups.AddDef("日期",DateGroupEnum.Year,"年")

 你确定是这句代码运行的时候，就出错？

 有出错的例子吗？

Dim dt As DataTable
Dim b As New SQLGroupTableBuilder("统计表1","订单")
b.ConnectionName = "sql"
b.Groups.AddDef("日期",DateGroupEnum.Year,"年")
b.Groups.AddDef("日期",DateGroupEnum.Month,"月")
b.Groups.AddDef("产品")
b.Totals.AddDef("产品",AggregateEnum.Count,"订单数") '根据主键列来统计记录数,也就是订单数
dt = b.Build(False) '参数设置为False,生成一个临时表,不在主界面显示
'然后根据统计表生成目录树
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree(dt, "年|月|产品")

For Each nd As winform.treenode  In trv.allnodes
    Dim sum As Integer = 0
    Select Case nd.level
        Case 0
            sum = dt.compute("sum(订单数)","年 = " & nd.DataRow("年"))
            nd.text = nd.text & "年(" & sum & "條)"
        Case 1
            sum = dt.compute("sum(订单数)","年 = " & nd.DataRow("年") & " and 月 = " & nd.DataRow("月"))
            nd.text = nd.text & "月(" & sum & "條)"
        Case 2
            sum = nd.DataRow("订单数")
            nd.text = nd.text & " (" & sum & "條)"
    End Select
Next
trv.nodes.Insert("顯示所有資料","顯示所有資料 (" & dt.compute("sum(订单数)") & "條)",0)

你的表里面没有 _Identify 列