add column value to an xml field as an attribute

Question

I would like to add an attribute value to an xml field in a query. my example is below

declare @table table (bookid int,xmlCol xml)
insert into @table
select 1,
'<book title="you are not alone" author="Esther">
  <EDITIONS>
    <edition year="2012"/>
    <edition year="2013"/>
  </EDITIONS>
</book>'

declare @table1 table(bookid int,quantity int)
insert into @table1
select 1,3 

select ??? 
from @table t
inner join @table1 t1
on t.bookid = t1.bookid

I want my final result to look like this

<book title="you are not alone" author="Esther" quantity="3">
  <EDITIONS>
    <edition year="2012"/>
    <edition year="2013"/>
  </EDITIONS>
</book>

Answer 1

IF you need select data, you can use xquery:

select
    t.xmlCol.query('
         element book {
             for $i in book/@* return $i,
             attribute quantity {sql:column("t1.quantity")},
             for $i in book/* return $i
         }
    ')
from @table t
    inner join @table1 t1 on t.bookid = t1.bookid

sql fiddle demo

or even simplier:

select
    t.xmlCol.query('
         element book {
             book/@*,
             attribute quantity {sql:column("t1.quantity")},
             book/*
         }
    ')
from @table t
    inner join @table1 t1 on t.bookid = t1.bookid

sql fiddle demo