判断select Count(ID)得到的记录数，当值为0，显示为空

[遊戲王千金]

目前的SQL：
select a.*,(select Count(ID) From uploadFile where objectType =a.TypeID) AS UploadFileCount From activity as a
就是弄不清楚，要如何加判断，当count记录数为零时，UploadFileCoun赋值作字符串''。

[飘零一叶]

select a.*,(select case when Count(ID)=0 then '' else Count(ID) end From uploadFile where objectType =a.TypeID) AS UploadFileCount From activity as a

[遊戲王千金]

谢谢Dlut_LIuQ的回复，用Count(ID)=0 then '',没有我要的效果，还是输出0,当我把''改成字符串 时候，报异常' ' 将varchar 值转换为数据类型int 的列时发生语法错误。
继续求解！！

[feixianxxx]

select a.*,
case when (select Count(ID) From uploadFile where objectType =a.TypeID)=0 then ''else 'a' end AS UploadFileCount
From activity as a

[飘零一叶]

select a.*,(select case when Count(ID)=0 then '' else ltrim(Count(ID)) end From uploadFile where objectType =a.TypeID) AS UploadFileCount From activity as a

[遊戲王千金]

果然是高手,可以了，我还用Convert函数试了n久.