I have a table with several columns, one of which is a xml
column. I do not have a namespace to use in the query. The XML data is always the same structure for all records.
create table #temp (id int, name varchar(32), xml_data xml)
insert into #temp values
(1, 'one', '<data><info x="42" y="99">Red</info></data>'),
(2, 'two', '<data><info x="27" y="72">Blue</info></data>'),
(3, 'three', '<data><info x="16" y="51">Green</info></data>'),
(4, 'four', '<data><info x="12" y="37">Yellow</info></data>')
Name Info.x Info.y Info
----- ------- ------- -------
one 42 99 Red
two 27 72 Blue
three 16 51 Green
four 12 37 Yellow
select Name, xml_data.query('/data/info/.').value('.', 'varchar(10)') as [Info]
from #temp
It returns the Name
and Info
columns. I cannot figure out how to extract the attribute values without using a namespace. For instance, the following queries returns errors:
select Name, xml_data.query('/data/info/@x') as [Info]
from #temp
Msg 2396, Level 16, State 1, Line 12
XQuery [#temp.xml_data.query()]: Attribute may not appear outside of an element
select Name, xml_data.value('/data/info/@x', 'int') as [Info]
from #temp
Msg 2389, Level 16, State 1, Line 12
XQuery [#temp.xml_data.value()]: 'value()' requires a singleton (or empty sequence), found operand of type 'xdt:untypedAtomic *'
select Name, xml_data.query('/data/info/.').value('@x', 'int') as [Info]
from #temp
Msg 2390, Level 16, State 1, Line 9
XQuery [value()]: Top-level attribute nodes are not supported
How do you write a query to return regular column data, and element + attribute values from an xml
column in the same table?
Just after I posted the question, I stumbled across this answer. Don't know why I couldn't find it in prior searches. It was the answer I was looking for. Here is the query that works:
select Name
,xml_data.value('(/data/info/@x)[1]', 'int') as [Info.x]
,xml_data.value('(/data/info/@y)[1]', 'int') as [Info.y]
,xml_data.value('(/data/info/.)[1]', 'varchar(10)') as [Info]
from #temp
Name Info.x Info.y Info
------- -------- -------- ---------
one 42 99 Red
two 27 72 Blue
three 16 51 Green
four 12 37 Yellow
.
I found another case that is worth adding to this answer. Given multiple <info>
elements within the <data>
element, it is possible to return all <info>
nodes by using cross apply
:
create table #temp (id int, name varchar(32), xml_data xml)
insert into #temp values
(1, 'one', '<data><info x="42" y="99">Red</info><info x="43" y="100">Pink</info></data>'),
(2, 'two', '<data><info x="27" y="72">Blue</info><info x="28" y="73">Light Blue</info></data>'),
(3, 'three', '<data><info x="16" y="51">Green</info><info x="17" y="52">Orange</info></data>'),
(4, 'four', '<data><info x="12" y="37">Yellow</info><info x="13" y="38">Purple</info></data>')
select Name
,C.value('@x', 'int') as [Info.x]
,C.value('@y', 'int') as [Info.y]
,C.value('.', 'varchar(10)') as [Info]
from #temp cross apply
#temp.xml_data.nodes('data/info') as X(C)
drop table #temp
This example returns the following dataset:
Name Info.x Info.y Info
--------- ----------- ----------- ----------
one 42 99 Red
one 43 100 Pink
two 27 72 Blue
two 28 73 Light Blue
three 16 51 Green
three 17 52 Orange
four 12 37 Yellow
four 13 38 Purple