Where Condition on XML column in sql

Suppose UserObject is XML Type column

 

Select ID,

   UserObject.value('(/UserDetail/UserName)[1]','nvarchar(250)') as UserName,

   UserObject.value('(/UserDetail/MailID)[1]','nvarchar(250)') as MailID,

   UserObject.value('(/UserDetail/City)[1]','nvarchar(250)') as City

 From [UserTable]

 

And

 

Select * From [UserTable] Where UserObject.exist('/UserDetail[City="London"]')=1