终于完成了人员汇总功能

 Dim strsql As String
        Dim daytoday As String
        daytoday = "日期>='" & Me.DateTimePicker1.Value & "' And 日期<= '" & Me.DateTimePicker2.Value & "' "
        ' MsgBox(daytoday)
        strsql = "select 人员编号,人员姓名,sum(合计)as '合计',公司 as '所在公司' from 出库单主表 where " & daytoday & "group by 人员编号,人员姓名,公司 order by 公司"
        ' MsgBox(strsql)
        Dim conn As New SqlConnection(My.Settings.药品数据ConnectionString)
        Try
            conn.Open()
        Catch ex As Exception
            MsgBox("数据库连接失败")
            End
        End Try
        Dim comd As New SqlCommand(strsql, conn)
        Dim reder As SqlDataReader = comd.ExecuteReader
        Dim tab1 As DataTable = New DataTable
        tab1.Load(reder) '直接载入reader
        Me.出库单主表DataGridView.DataSource = tab1