如何替换xml类型字段的多个属性值

SQL code

 
 DECLARE @myDoc xml 
 SET @myDoc = ' <Root> 
  <Location LocationID="10"  
             LaborHours="1.1" 
             MachineHours=".2" >Manufacturing steps are described here. 
  <step>Manufacturing step 1 at this work center </step> 
  <step>Manufacturing step 2 at this work center </step> 
  </Location> 
  </Root>' 
 SELECT @myDoc 
 -- update attribute value 
 SET @myDoc.modify(' 
   replace value of (/Root/Location/@LaborHours)[1] 
   with     "100.0" 
 ') 
 SELECT @myDoc 
  
 

查MSDN知道，replace value of ...可以用来替换xml类型的值，
示例也是摘抄MSDN的，如果要在一条sql里完成对LocationID，LaborHours，MachineHours属性的修改，应该怎么做？

我说过写多条 replace value of (...) with "" 不行。

------解决方案--------------------
DECLARE @myDoc xml
SET @myDoc = '<Root>
<Location LocationID="10" 
LaborHours="1.1"
MachineHours=".2" >Manufacturing steps are described here.
<step>Manufacturing step 1 at this work center</step>
<step>Manufacturing step 2 at this work center</step>
</Location>
</Root>'
SELECT @myDoc
-- update attribute value
SET @myDoc.modify('
replace value of (/Root/Location/@LaborHours)[1]
with "100.0"
')
SET @myDoc.modify('
replace value of (/Root/Location/@MachineHours)[1]
with "100.0"
')

SELECT @myDoc