SQL语句   case when then
有两个SUM字段,SQL语句大概为
select····
     sum(number1),
     sum(number2)
from tablename
where`````
现在用case when 再加一个字段 当sum(number1)-sum(number2)>=0时,字段值为 “大于零 +数字(数字值就是 sum(number1)=sum(number2)的值) ”   当sum(number1)-sum(number2)>=0时
字段值为“小于零+数字”   
这个字段的SQL怎么写?
------解决方案--------------------
汗,老漏东西
select····
 sum(number1),
 sum(number2),
 case when (sum(number1)-sum(number2)>=0) then	'大于零'+convert(varchar(50),(sum(number1)-sum(number2)))
      when (sum(number1)-sum(number2)<0) then	'小于零'+convert(varchar(50),(sum(number1)-sum(number2)))
 else NULL end  
from tablename
where`````