TSQL Parse from XML nodes - sql-server

Question

This XML comes from public treasury. SQL Server seems to think it is not XML? My result says the XLT method can only be involved with column type XML. Is this result set from the treasury really XML?
How can I parse it into a SQL table?
treasury daily market yield
DECLARE #XML NVARCHAR(MAX)
SELECT #XML =
'<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<feed xml:base="http://data.treasury.gov/Feed.svc/" xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns="http://www.w3.org/2005/Atom">
<title type="text">DailyTreasuryYieldCurveRateData</title>
<id>http://data.treasury.gov/feed.svc/DailyTreasuryYieldCurveRateData</id>
<updated>2020-07-14T05:40:26Z</updated>
<link rel="self" title="DailyTreasuryYieldCurveRateData" href="DailyTreasuryYieldCurveRateData"/>
<entry>
<id>http://data.treasury.gov/Feed.svc/DailyTreasuryYieldCurveRateData(7633)</id>
<title type="text"/>
<updated>2020-07-14T05:40:26Z</updated>
<author>
<name/>
</author>
<link rel="edit" title="DailyTreasuryYieldCurveRateDatum" href="DailyTreasuryYieldCurveRateData(7633)"/>
<category term="TreasuryDataWarehouseModel.DailyTreasuryYieldCurveRateDatum" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme"/>
<content type="application/xml">
<m:properties>
<d:Id m:type="Edm.Int32">7633</d:Id>
<d:NEW_DATE m:type="Edm.DateTime">2020-07-01T00:00:00</d:NEW_DATE>
<d:BC_1MONTH m:type="Edm.Double">0.12</d:BC_1MONTH>
<d:BC_2MONTH m:type="Edm.Double">0.12</d:BC_2MONTH>
<d:BC_3MONTH m:type="Edm.Double">0.14</d:BC_3MONTH>
<d:BC_6MONTH m:type="Edm.Double">0.17</d:BC_6MONTH>
<d:BC_1YEAR m:type="Edm.Double">0.16</d:BC_1YEAR>
<d:BC_2YEAR m:type="Edm.Double">0.17</d:BC_2YEAR>
<d:BC_3YEAR m:type="Edm.Double">0.19</d:BC_3YEAR>
<d:BC_5YEAR m:type="Edm.Double">0.31</d:BC_5YEAR>
<d:BC_7YEAR m:type="Edm.Double">0.52</d:BC_7YEAR>
<d:BC_10YEAR m:type="Edm.Double">0.69</d:BC_10YEAR>
<d:BC_20YEAR m:type="Edm.Double">1.2</d:BC_20YEAR>
<d:BC_30YEAR m:type="Edm.Double">1.43</d:BC_30YEAR>
<d:BC_30YEARDISPLAY m:type="Edm.Double">1.43</d:BC_30YEARDISPLAY>
</m:properties>
</content>
</entry>
</feed>'
SELECT b.value('#d:Id', 'varchar(28)') as d_id
,b.value('#d:BC_30YEAR', 'double') as d_BC_30YEAR
FROM #XML.nodes('feed/entry/content type/m:properties/') as a(b)

Answer 1

First, define your #XML to be of type XML:
DECLARE #XML XML;
Then: you need to define the relevant XML namespaces involved!
Try this snippet of code:
-- define XML namespaces!
;WITH XMLNAMESPACES(DEFAULT 'http://www.w3.org/2005/Atom',
'http://schemas.microsoft.com/ado/2007/08/dataservices/metadata' AS m,
'http://schemas.microsoft.com/ado/2007/08/dataservices' AS d)
SELECT
b.value('(d:Id)[1]', 'varchar(28)') as d_id,
b.value('(d:BC_30YEAR)[1]', 'decimal(20,2)') as d_BC_30YEAR
FROM
#XML.nodes('feed/entry/content/m:properties') as a(b)
This returns the following value:
Fixes I made:
FROM #XML.nodes('feed/entry/content type/m:properties/') as a(b)
^^^^^^^^^^^^
Wrong node name - the node is <content> (not "content type") - the type is just an attribute on the node, no relevant in this XPath here.
SELECT b.value('#d:Id', 'varchar(28)') as d_id
^^^^^^
You really want to select the XML element (node) d:Id - not an attribute - the # in #d:Id denotes an attribute!
b.value('#d:BC_30YEAR', 'double') as d_BC_30YEAR
^^^^^^^^^
You need to use a proper T-SQL datatype - like decimal(20,2) - not "double"
here....