select case语句

"select id,name,discount,author,price,type ,image=case when(not Cover is null) then ' <img src=ReadBookCover.aspx?id='+cast(id as

varchar(10))+' Border=1 width=80 height=120>' else ' <img src=img/pic.jpg border=1 width=80 height=120>' end from book where

type="+BookTypeId

strsql="select top 10 id,name,descr='&nbsp;&nbsp;'+SUBSTRING(description,0,100)+'......',image=case when(not Cover is null) then '

<img src=ReadBookCover.aspx?id='+cast(id as varchar(10))+' Border=1 width=70 height=100>' else ' <img src=img/pic.jpg border=1

width=70 height=100>' end from book order by hits DESC";

strSQL = "SELECT UserId, OrderDate,CASE WHEN Status = '1' THEN 'dealt' ELSE 'on progress' END AS Status FROM Orders Where Id=" +

orderId.ToString();