如果避免显示重复数据

Question

我做了如下的一个Repeater，用于显示大量的“日期”、“名称”对应数据，因为同一天有很多的数据，我想只让这天的最后（或者最先）的一条数据显示日期，而其他的数据前都不显示日期，不知道应该如何做呢？<br><br><div class="resourceSection"> <asp:Label id="lbSectionName" runat="server"></asp:Label> <asp:Repeater id="rptSectionData" runat="server"> <HeaderTemplate> </HeaderTemplate></asp:Repeater><table class="resourceTable mceVisualAid"> <ItemTemplate> </ItemTemplate><tbody><tr class="sectionRowOdd"> <td class="mceVisualAid">&lt;%# Eval("AddTime", "{0:yyyy-MM-dd}")%&gt;</td> <td class="mceVisualAid">&lt;%# Eval("OriginName")%&gt;_&lt;%# Eval("ChineseName")%&gt;</td> </tr> <AlternatingItemTemplate> </AlternatingItemTemplate><tr class="sectionRowEven"> <td class="mceVisualAid">&lt;%# Eval("AddTime", "{0:yyyy-MM-dd}")%&gt;</td> <td class="mceVisualAid">&lt;%# Eval("OriginName")%&gt;_&lt;%# Eval("OriginName")%&gt;</td> </tr> <FooterTemplate> </FooterTemplate></tbody></table> </div>

Answer 1

这个问题可以通过写sql解决，我给你提供一种sql2005下的一种写法。 假定你有一张表TA，有三个字段ID，AddTime,OriginName [code] if object_id('ta','U') is not null drop table ta; go create table ta( id int identity(1,1) not null , OriginName nvarchar(100) not null, AddTime datetime not null ) go insert into ta values('A','2008-05-01 10:10:11'); insert into ta values('B','2008-05-01 20:10:11'); insert into ta values('C','2008-05-02 09:10:11'); insert into ta values('D','2008-05-02 15:10:11'); insert into ta values('E','2008-05-03 11:10:11'); Go with ta_temp as( select id, originName,AddTime, datePartOfAddTime = cast(year(AddTime) as char(4)) + '-' + cast(month(AddTime) as char(2)) + '-' + cast(day(AddTime) as char(2)) FROM ta ), ta_temp_rn as( SELECT id,originName,AddTime,datePartOfAddTime, rn = ROW_NUMBER() OVER (PARTITION BY datePartOfAddTime ORDER BY AddTime DESC) FROM ta_temp ) SELECT id,originName,AddTime FROM ta_temp_rn WHERE rn = 1 [/code] 以上脚本已测试通过，取每天的第一条，或者最后一条，只需修改 [code] ROW_NUMBER() OVER (PARTITION BY datePartOfAddTime ORDER BY AddTime DESC) [/code] 中的ORDER BY AddTime DESC 或者ASC即可。 sql 2000中写法如下： [code] select ta.* from ta inner join ( select maxAddTime = max(AddTime), datePartOfAddTime = cast(year(AddTime) as char(4)) + '-' + cast(month(AddTime) as char(2)) + '-' + cast(day(AddTime) as char(2)) FROM ta group by cast(year(AddTime) as char(4)) + '-' + cast(month(AddTime) as char(2)) + '-' + cast(day(AddTime) as char(2)) ) temp on ta.addtime = temp.maxAddTime [/code] 2000中写法的效率肯定要低于2005中的。