N个dataset的合并

 Try
            '得到姓名，工号
            Dim wr As WebReference.EipUserServices = New WebReference.EipUserServices
            Dim str_result As String = wr.GetUserTable   '接收返回的XML文本
            '将XML文本导入已实例化的Dataset
            Dim myds As DataSet = New DataSet
            Dim stringreadr As System.IO.StringReader = New System.IO.StringReader(str_result)
            Dim xmltextrder As System.Xml.XmlTextReader = New System.Xml.XmlTextReader(stringreadr)
            myds.ReadXml(xmltextrder)

            Dim tt9 As String = "%" + Me.TextBox1.Text.Trim + "%"

            '将工号读出来
            mysql = "SELECT a.TableSort, b.BDName, a.UserCode, a.State "
            mysql &= " FROM Not_Email a INNER JOIN BasicData b ON a.TableSort = b.BDCode"
            mysql &= " WHERE (b.DataSort = 'A') AND ((b.BDName LIKE @BDName) OR (a.UserCode LIKE @UserCode)) ORDER BY a.TableSort"
            mycomm = New SqlCommand(mysql, myconn1)

            mycomm.Parameters.Add("@UserCode", tt9.Trim)
            mycomm.Parameters.Add("@BDName", tt9.Trim)

            myda = New SqlDataAdapter(mycomm)
            ds.Tables.Clear()
            myconn1.Open()
            myda.Fill(ds, "T1")

            Dim t3 As DataTable
            Dim tr As DataRow
            Dim i, j, k As Int16

            t3 = New DataTable("t3")
            For i = 0 To 5
                t3.Columns.Add(New DataColumn("C" + i.ToString))
            Next
            '将记录T1写到对应的T3列中
            For i = 0 To ds.Tables("T1").Rows.Count - 1
                tr = t3.NewRow
                tr(0) = ds.Tables("T1").Rows(i).Item(0)
                tr(1) = ds.Tables("T1").Rows(i).Item(1)
                tr(2) = ds.Tables("T1").Rows(i).Item(2)
                tr(3) = ds.Tables("T1").Rows(i).Item(3)
                t3.Rows.Add(tr)
            Next

            '扫描web 得到的用户表，将使用记录写入T3对应的行中
            Dim gh As String
            Dim rowno As Int16
            For i = 0 To myds.Tables(0).Rows.Count - 1
                gh = myds.Tables(0).Rows(i).Item(2) '工号

                '在T3中查找名为mycode的会议室所在的行号，然后将从T2复制到T3
                For j = 0 To t3.Rows.Count - 1
                    If t3.Rows(j).Item(2) = gh Then
                        If CStr(myds.Tables(0).Rows(i).Item(0)).Trim = "" Then
                        Else
                            t3.Rows(j).Item(4) = myds.Tables(0).Rows(i).Item(0)
                        End If

                    End If
                Next
            Next

            Dim ii As Integer
            '  Dim i As Integer
            ii = t3.Rows.Count
            ii = ii Mod 20
            If ii < 10 Then
                For i = 0 To 10 - ii
                    t3.Rows.Add(t3.NewRow)
                Next
            End If

            '将T3绑定到datagrid
            Me.DataGrid1.DataSource = t3.DefaultView
            Me.DataGrid1.DataBind()

            myconn1.Close()
        Catch ex As Exception
            Me.Label1.Text = "出错了：<br>在读取数据库时出现异常，数据读取失败！<br>原因事:" + ex.Message
        End Try