查询出来的数据怎样进行二次查询

[fjh525]

在查询一个表后，把查询出来的DataTable绑定到GridView里，如何在GridView里面再次根据条件查询，最好不是去查询数据库，以前听人说可以用ViewState,但我不会！很少用到ViewState

另：我在用ViewState的时候，用dt.Select查询出来的是一个DataRow数组，能把这个数组弄成DataTable类型吗？还有，在DataRow里面查询出来的值 ，好像没有那个自动序列的ID！

谁会这方面的东西麻烦回答写详细点，或直接发段代码看看！谢谢各位大大了！

[the_pain]

DataTable dt = new DataTable();
dt = ds.Tables[0];
DataRow[] dr = dt.Select("EquipmentID='" + sbid + "'");
DataView dv = new DataView(dt);
dv.RowFilter = "EquipmentID='" + sbid + "'";
this.GridView1.DataSource = dv;
this.GridView1.DataBind();

[CutBug]

用DataView RowFilter
DataView dv = new DataView(GridView.DataSource as DataTable);
dv.Sort = "";
dv.RowFilter = "";
GridView.DataSource = dv ;//重新绑定
GridView.DataBind();

[阿云ivan]

你可以重新new一个datatable,用来存放Select查询出来的DataRow数组呀

[chinawes]

ViewState是页面级变量，类似session，只是ViewState在当前页面可用。
你可以把查询出来的DataTable类型的值用ViewState保存，如下：
ViewState["dt"] = dt;
取值的时候
DataTabel dt = ViewState["dt"] as DataTabel,
然后 DataRow[] drs = dt.Select("column1 is null");
笨方法的话，可以把数组遍历手动添加个DataTabel.
最后把组合的DataTabel绑定到GridView。

[阿非]

<asp:GridView ID="gv1" runat="server"></asp:GridView>

protected DataTable getDataTableDepartment()
    {

        System.Data.DataTable dt = new System.Data.DataTable();
        System.Data.DataRow dr;
        dt.Columns.Add(new System.Data.DataColumn("ID", typeof(System.Int32)));
        dt.Columns.Add(new System.Data.DataColumn("Caption", typeof(System.String)));
        dt.Columns.Add(new System.Data.DataColumn("ManagerID", typeof(System.Int32)));
        dr = dt.NewRow();
        dr[0] = 1;
        dr[1] = "A";
        dr[2] = 1;
        dt.Rows.Add(dr);
        dr = dt.NewRow();
        dr[0] = 2;
        dr[1] = "B";
        dr[2] = 1;
        dt.Rows.Add(dr);
        dr = dt.NewRow();
        dr[0] = 3;
        dr[1] = "C";
        dr[2] = 1;
        dt.Rows.Add(dr);
        dr = dt.NewRow();
        dr[0] = 4;
        dr[1] = "D";
        dr[2] = 2;
        dt.Rows.Add(dr);
        dr = dt.NewRow();
        dr[0] = 5;
        dr[1] = "E";
        dr[2] = 2;
        dt.Rows.Add(dr);
        return dt;
    }
protected void Page_Load(object sender, EventArgs e)
    {
        DataView dv = getDataTableDepartment().DefaultView;
        dv.RowFilter = "ManagerID=1";
        gv1.DataSource = dv.Table;
        gv1.DataBind();
    }

[我姓区不姓区]

[Quote=引用 2 楼 CutBug 的回复:]
用DataView RowFilter
DataView dv = new DataView(GridView.DataSource as DataTable);
dv.Sort = "";
dv.RowFilter = "";
GridView.DataSource = dv ;//重新绑定
GridView.DataBind();


[/Quote]
up

[金大哈]

简单查询可以如下：效率高的

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
/* QQ312430633 创建日期:2008-06-25 */ 
--修改了ORDER BY 需要 percent 与 ORDERBY 失效的BUG--
---注意'roder by'用一个空格间隔

Create PROCEDURE  [dbo].[les_AllowPaging] 
@pageindex int,    ----*****页码
@PageSize int,     ----*****每页显示条数
@tsql varchar(4000)----*****SQL语句
as

Declare @SqlSelect  varchar(4000)
Declare @orderby  varchar(4000)
Declare @AllowPagingSql  varchar(4000) 

---判断是否排序
if CHARINDEX('order by',@tsql) <> 0
begin
    set @SqlSelect=replace(substring (@tsql,1, CHARINDEX('order by',@tsql)-1),'$','''')  
    set @orderby=replace(substring (@tsql, CHARINDEX('order by',@tsql),len(@tsql) ),'$','''')      
    set @AllowPagingSql=
        'select * from (SELECT  ROW_NUMBER() OVER('+@orderby+') AS AllowPagingId,* FROM ('+
        @SqlSelect
        +') as table1) as table2 where AllowPagingId between '
        +convert(varchar(10),((@pageindex-1) * @PageSize+1))+' and '
        +convert(varchar(10), @pageindex * @PageSize)         
    exec  (@AllowPagingSql)
end 
else
begin
    set @SqlSelect=replace(@tsql,'$','''')  
    set @orderby=''
    set @AllowPagingSql=
        'select *  from (SELECT  *,ROW_NUMBER() OVER(ORDER BY orderbyID DESC) AS AllowPagingId FROM  ( select *, 1 as orderbyID from ( '
        +@SqlSelect
        +' )  as  tbs1 )   as Tabl1 ) as table2 where AllowPagingId between '
        +convert(varchar(10),((@pageindex-1) * @PageSize+1))+' and '
        +convert(varchar(10), @pageindex * @PageSize)         
        exec  (@AllowPagingSql)
end

set @AllowPagingSql='select 
case 
     when count(*)%'+convert(varchar(10),@PageSize)+'=0 then count(*)/'+convert(varchar(10),@PageSize)+'
     when count(*)%'+convert(varchar(10),@PageSize)+'<>0 then count(*)/'+convert(varchar(10),@PageSize)+'+1
end as pageCount,count(*) as RowsCount from ('+@SqlSelect+') as tab1'
exec  (@AllowPagingSql)