Checking a xml node value in sql

Question

Hi,

 

I have a table named Sales, there is a column as xmldata. xmldata is as below

 

 

<data>

<product>

<area>

<pincode>110001</pincode>

<state>delhi</state>

<country>india</country>

</area> 

</product>

</data>

<data>

<product>

<area>

<pincode>411004</pincode>

<state>pune</state>

<country></country>

</area>

</product>

</data>

 

 

in some records country is missing. please provide an sql query to check whether country is null or not