sqlserver 2008 dateadd函数问题

[chenyayun77]

select booking.id as id,orderno ,productName as pno,phone as user1,quantity as pnumber,productCombo
as taocan,unit as pjiage ,residual as zjiage,privilege as pfanxian,CustomerName as senduser,case AddedService
when '一年延' then '一年' when '二年延' then '两年' else AddedService end as fuwu,tel,mail
as email,CustomerAddress as address,residual as jiage,
case booking.lasteditdate > dateadd(day,-7,getdate())
when true then '交易成功' else '确认收货' end

case booking.lasteditdate > dateadd(day,-7,getdate())
提示：'>' 附近有语法错误。

when true then '交易成功' else '确认收货' end
提示：列名‘true’无效。
找了很久，就是没找到答案，现在求各位大大帮忙看看。谢谢！

[骑着蜗牛去爬山]

case when booking.lasteditdate > dateadd(day,-7,getdate()) then '交易成功' else '确认收货' end

[叶子]

SELECT  booking.id AS id ,
        orderno ,
        productName AS pno ,
        phone AS user1 ,
        quantity AS pnumber ,
        productCombo AS taocan ,
        unit AS pjiage ,
        residual AS zjiage ,
        privilege AS pfanxian ,
        CustomerName AS senduser ,
        CASE AddedService
          WHEN '一年延' THEN '一年'
          WHEN '二年延' THEN '两年'
          ELSE AddedService
        END AS fuwu ,
        tel ,
        mail AS email ,
        CustomerAddress AS address ,
        residual AS jiage ,
        CASE WHEN booking.lasteditdate > DATEADD(day, -7, GETDATE())
             THEN '交易成功'
             ELSE '确认收货'
        END