Formatting sql correctly tp produce expected xml output - sql-server

Thanks to a fellow SO user I'm making progress with FOR XML, but I'm clearly not quite getting the sql syntax correct.
Let's say that I have the following sql
DECLARE #Uname VARCHAR(15) = 'Dom',
#Pword VARCHAR(15) = 'Monty'
SELECT
RTRIM(#Uname) AS '#uname',
RTRIM( #Pword) AS '#pword',
(SELECT COALESCE(PortOfLanding,'') AS portOfLanding
FROM Landings.LandingHeaders
WHERE Posted = 0
FOR XML PATH('Sale'))
FOR XML PATH('abc')
When run it produces the following as its output
<abc uname="Dom" pword="Monty"><Sale><portOfLanding>GBHTG</portOfLanding></Sale><Sale><portOfLanding>GBHTG</portOfLanding></Sale></abc>
What I was really hoping for though was the following
<abc uname="Dom" pword="Python">
<Sale portOfLanding= "GBHTG" />
<Sale portOfLanding= "GBHTG"/>
</abc>
and in fact I would like to add a third section to the SQL so that eventually one might end up with xml like so
<abc uname="Dom" pword="Python">
<Sale portOfLanding= "GBHTG">
<saleline detail="some value here" />
<saleline detail="some value here" />
<Sale/>
<Salesnote portOfLanding= "GBHTG"/>
</abc>
Can someone point out where I've gone wrong in the original SQL query?
Thanks

Try this:
DECLARE #Uname VARCHAR(15) = 'Dom',
#Pword VARCHAR(15) = 'Monty';
SELECT RTRIM(#Uname) AS '#uname',
RTRIM( #Pword) AS '#pword',
(SELECT COALESCE(PortOfLanding,'') AS '#portOfLanding'
FROM Landings.LandingHeaders
WHERE Posted = 0
FOR XML PATH('Sale'), TYPE)
FOR XML PATH('abc')
You can go deeper like:
SELECT RTRIM(#Uname) AS '#uname',
RTRIM( #Pword) AS '#pword',
(SELECT COALESCE(PortOfLanding,'') AS '#portOfLanding',
(SELECT COALESCE(PortOfLanding,'') AS '#detail'
FROM Landings.LandingHeaders
FOR XML PATH('SaleLine'), TYPE)
FROM Landings.LandingHeaders
WHERE Posted = 0
FOR XML PATH('Sale'), TYPE)
FOR XML PATH('abc')

Related

XML output in SQL help needed

Hi I have the following code in SQL that outputs xml between 2 tables. The output is 90% correct but if possible add to the output and then also remove some of the output text.
I am not sure if SQL has the ability to code a type of a element in the output. Please see the code below with the output. Currently if possible I would like to make 2 changes to my current output. The changes are list at the end of the port
DECLARE #ID_Rechnung int = 1978,
#XMLData xml;
WITH XMLNAMESPACES ('?xml version="1.0" encoding="UTF-8"?' as ext)
SELECT
#XMLData = xmldat.xmldataCol
FROM
(
SELECT (
SELECT
-- HIER XML Daten generieren
[InvoiceHeader].[InvoiceDate] AS 'invoice-date',
([InvoiceHeader].[InvoiceNumber]) AS 'invoice-number',
cast(replace([InvoiceHeader].[GrossValue],' ','') as decimal(18,2)) AS 'gross-total',
cast(replace([InvoiceHeader].[NetValue],' ','') as decimal(18,2)) AS 'amount-due',
[InvoiceHeader].[VatRate] AS 'tax-rate',
cast(replace([InvoiceHeader].[VatValue],' ','') as decimal(18,2)) AS 'tax-amount',
[ImagePath] AS 'image-scan-url',
[InvoiceType] AS 'document-type',
[LegalEntityVATNo] AS 'account-type/id',
[LegalEntityName] AS 'account-type/name',
[SupplierCode] as 'supplier/number',
[Currency] as 'currency/code',
(
SELECT rtrim([InvoiceLines].[LineNumber]) AS [order-line-num]
, [PONumber] as [po-number],
CAST([InvoiceLines].[UnitPrice] AS decimal(18,2)) AS Price ,
[Quantity] as quantity,
[TaxAmount] as [tax-amount],
[LineTotal] as [total],
[Decsription] as description
FROM [InvoiceLines] WHERE [InvoiceLines].[DOCID] = #id_Rechnung
FOR XML PATH('Invoice-line'), ROOT('invoice-lines'), TYPE
)
FROM [InvoiceHeader]
WHERE [InvoiceHeader].[DOCID] = #ID_Rechnung
FOR XML PATH(''), TYPE, ROOT('invoice-header')
) AS xmldataCol
) AS xmldat;
SELECT #XMLData
.query('<invoice-header>
{
for $x in /invoice-header/*[local-name()!="root"]
return $x,
for $x in /invoice-header/root/r
return <invoice-lines>/<invoice-line>{$x/*}</invoice-line></invoice-lines>
}
</invoice-header>');
Output:
<invoice-header>
<invoice-date>20180509</invoice-date>
<invoice-number>1075440</invoice-number>
<gross-total>1376.67</gross-total>
<amount-due>1197.10</amount-due>
<tax-rate>15.00%</tax-rate>
<tax-amount>179.57</tax-amount>
<image-scan-url>\\INTEL-SQL01\Attachment\2018-06-20\7e0dd165-81d6-445a-95d1-8aac686d44ed\f9a1179c-2a54-480e-b97a-ce6ac7327ae0.000</image-scan-url>
<account-type>
<id>4010112052</id>
<name>CONSOLIDATEDPOWERPROJECTS</name>
</account-type>
<supplier>
<number>12345</number>
</supplier>
<currency>
<code>ZAR</code>
</currency>
<invoice-lines xmlns:ext="?xml version="1.0" encoding="UTF-8"?">
<Invoice-line>
<order-line-num>4</order-line-num>
<po-number>120934861</po-number>
<Price>50.00</Price>
<quantity>1.000000</quantity>
<tax-amount>7.500000</tax-amount>
<total>50.00</total>
<description>Test1</description>
</Invoice-line>
<Invoice-line>
<order-line-num>2</order-line-num>
<po-number>120934861</po-number>
<Price>10.00</Price>
<quantity>2.000000</quantity>
<tax-amount>4.500000</tax-amount>
<total>20.00</total>
<description>Test2</description>
</Invoice-line>
</invoice-lines>
</invoice-header>
1.How do I get rid of the following xmlns:ext="?xml version="1.0" encoding="UTF-8&in the line: "<invoice-lines xmlns:ext="?xml version="1.0" encoding="UTF-8"?">"
How would I code "<tax-amount>7.500000</tax-amount> to get the output": "<tax-amount type="decimal">7.500000</tax-amount>"
Without a minimal reproducible example it is not possible to give you a full working answer.
(1) As #JeroenMostert already pointed out, the
'?xml version="1.0" encoding="UTF-8"?'
is an XML prolog declaration. Just delete the following line:
WITH XMLNAMESPACES ('?xml version="1.0" encoding="UTF-8"?' as ext)
(2) Here is a conceptual example how to add an attribute to an XML element. What is important here is a sequential order of adding, i.e. attribute shall be first, element itself is 2nd.
SQL
DECLARE #tbl TABLE (ID INT IDENTITY PRIMARY KEY, [tax-amount] VARCHAR(20));
INSERT INTO #tbl ([tax-amount]) VALUES
(N'7.500000'),
(N'18.000000');
SELECT
'decimal' AS [tax-amount/#type]
, [tax-amount]
FROM #tbl
FOR XML PATH('r'), TYPE, ROOT('root');
Output
<root>
<r>
<tax-amount type="decimal">7.500000</tax-amount>
</r>
<r>
<tax-amount type="decimal">18.000000</tax-amount>
</r>
</root>

Manipulate XMLNamespaces

I have the following output from SQL using FOR XML clause:
<q17:DestinationSection xmlns:q17="http://ITrack.Transmission/2011/02/25/Objects">
<q17:DestinationCode>1</q17:DestinationCode>
<q17:DestinationName>Strada Rampei 9, Iasi</q17:DestinationName>
<q17:DestinationAddress1>Strada Rampei 9, Iasi</q17:DestinationAddress1>
<q17:DestinationAddress2>
xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
</q17:DestinationAddress2>
</q17:DestinationSection>
The DestinationSection is the main root for this block of data. Is there any possibility to do some workaround and to have something like below in the <q17:DestinationAddress2></q17:DestinationAddress2> tag?
<q17:DestinationAddress2 xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"</q17:DestinationAddress2>
I have tried something but I get an error that says that I need to declare the namespace but I really don't know where to "introduce" that definition.
My SQL statement
DECLARE #XMLFINAL VARCHAR(MAX)
SET #XMLFINAL=''
DECLARE #XMLFINAL2 VARCHAR(MAX)
SET #XMLFINAL2=''
DECLARE #NUMBER NVARCHAR(100)
DECLARE #NUMBER2 NVARCHAR(100)
DECLARE #XML VARCHAR(MAX)
DECLARE #XML2 VARCHAR(MAX)
DECLARE Rec CURSOR FAST_FORWARD FOR
SELECT GID FROM PurchaseDocumentsHeader
OPEN Rec
FETCH NEXT FROM Rec INTO #NUMBER2
WHILE ##FETCH_STATUS = 0
BEGIN
SET #XML2=''
;WITH XMLNAMESPACES ('http://ITrack.Transmission/2011/02/25/Objects' as q17)
SELECT #XML2= (
SELECT
DestCode AS 'q17:DestinationCode', DestDescr 'q17:DestinationName', DestAddr AS 'q17:DestinationAddress1', DestAddr2 AS 'q17:DestinationAddress2',
DestZIP AS 'q17:DestinationZIP'
FROM PurchaseDocumentsHeader WHERE GID=#NUMBER2
FOR XML RAW('q17:DestinationSection'),ELEMENTS
)
FETCH NEXT FROM Rec INTO #NUMBER2
SET #XMLFINAL2=#XMLFINAL2+#XML2
END
CLOSE Rec DEALLOCATE Rec
EDIT
Please find below my DDL. It's a view used to extract the data from an official table.
CREATE VIEW [dbo].[PurchaseDocumentsHeader]
AS
SELECT esd.GID, esd.ADRegistrationDate, esgo.Code AS DestCode, esgo.Description AS DestDescr, esgo.Address1 AS DestAddr, esgo.fCityCode AS DestCity,
esgp.TaxRegistrationNumber AS DestZIP, 'xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"' AS DestAddr2, esgo.Description AS DestRomanized,
esgo.Address1 AS DestAddress1Romanized,
'xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"' AS DestAddress2Romanized, esgp.TaxRegistrationNumber AS DestZIPRom,
esgo.fCityCode AS DestCityRomanized, esgo.fCountryCode AS DestCountry, cast('DestinationGLN xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>' AS XML) AS DestGLN,
'xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"' AS DestCoord
FROM ESFIDocumentTrade esd
LEFT JOIN ESGOSites esgo on esd.fDeliverySiteGID=esgo.GID
LEFT JOIN ESFITradeAccount esc on esd.fTradeAccountGID=esc.GID
LEFT JOIN ESGOPerson esgp on esc.fPersonCodeGID=esgo.GID
LEFT JOIN ESFIDocumentType est on esd.fADDocumentTypeGID=est.GID
WHERE esd.fTransitionStepCode='APPROVED' AND est.Code='CVR'
AND YEAR(esd.ADRegistrationDate)=YEAR(GETDATE())
AND MONTH(esd.ADRegistrationDate)=MONTH(GETDATE())
AND DAY(esd.ADRegistrationDate)=DAY(GETDATE())
GO
Later edit
CREATE TABLE DocPurcharseHeader
(
ADRegistrationDate date,
Code NVARCHAR(4000),
Description NVARCHAR(4000),
Address1 NVARCHAR (4000),
Address2 NVARCHAR (4000),
City NVARCHAR (4000),
ZIPCode NVARCHAR(4000)
)
INSERT INTO DocPurcharseHeader (ADRegistrationDate, Code, Description, Address1, Address2, City, ZIPCode)
VALUES('2017-10-16', '01', 'MyPOS', 'MyPOSAddress1', 'MyPOSAddress2', 'BUCHAREST', '123456')
2nd Later edit
;WITH XMLNAMESPACES ('http://ITrack.Transmission/2011/02/25/Objects' as q17)
SELECT #XMLSalesOrders=(
SELECT DestCode AS [q17:DestinationCode]
,DestDescr AS [q17:DestinationName]
,DestAddr AS [q17:DestinationAddress1]
,DestAddr2 AS [q17:DestinationAddress2]
FROM PurchaseDocumentsHeader
FOR XML PATH('q17:DestinationSection'),ELEMENTS XSINIL,ROOT('q17:DestinationSections'))
This code above is generating the below output, without XSINL directive:
<q17:DestinationSections xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:q17="http://ITrack.Transmission/2011/02/25/Objects">
<q17:DestinationSection>
<q17:DestinationCode>1</q17:DestinationCode>
<q17:DestinationName>Strada Rampei 9, Iasi</q17:DestinationName>
<q17:DestinationAddress1>Strada Rampei 9, Iasi</q17:DestinationAddress1>
<q17:DestinationAddress2/>
</q17:DestinationSection>
<q17:DestinationSection>
you are trying to out-trick the very mighty XML engine.
As stated in your other question:
Never do this in a CURSOR! They are bad and evil, coming directly of the hell of procedural thinking and were invented by the devil of spaghetti code...
Try it like this:
I use your table DDL an insert some data. The second row will have a NULL in address2. Normally XML will simply omit NULL values. A not existing node is read as a NULL value. But you can force NULLs to be introduced as xsi.nil="true" with ELEMENTS XSINIL:
CREATE TABLE DocPurcharseHeader
(
ADRegistrationDate date,
Code NVARCHAR(4000),
Description NVARCHAR(4000),
Address1 NVARCHAR (4000),
Address2 NVARCHAR (4000),
City NVARCHAR (4000),
ZIPCode NVARCHAR(4000)
);
INSERT INTO DocPurcharseHeader (ADRegistrationDate, Code, Description, Address1, Address2, City, ZIPCode)
VALUES('2017-10-16', '01', 'MyPOS', 'MyPOSAddress1', 'MyPOSAddress2', 'BUCHAREST', '123456')
,('2017-10-16', '01', 'MyPOS', 'MyPOSAddress1', NULL, 'BUCHAREST', '123456');
WITH XMLNAMESPACES('http://ITrack.Transmission/2011/02/25/Objects' AS q17)
SELECT Code AS [q17:DestinationCode]
,Description AS [q17:DestinationName]
,Address1 AS [q17:DestinationAddress1]
,Address2 AS [q17:DestinationAddress2]
FROM DocPurcharseHeader
FOR XML PATH('q17:DestinationSection'),ELEMENTS XSINIL,ROOT('q17:DestinationSections');
The result
<q17:DestinationSections xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:q17="http://ITrack.Transmission/2011/02/25/Objects">
<q17:DestinationSection>
<q17:DestinationCode>01</q17:DestinationCode>
<q17:DestinationName>MyPOS</q17:DestinationName>
<q17:DestinationAddress1>MyPOSAddress1</q17:DestinationAddress1>
<q17:DestinationAddress2>MyPOSAddress2</q17:DestinationAddress2>
</q17:DestinationSection>
<q17:DestinationSection>
<q17:DestinationCode>01</q17:DestinationCode>
<q17:DestinationName>MyPOS</q17:DestinationName>
<q17:DestinationAddress1>MyPOSAddress1</q17:DestinationAddress1>
<q17:DestinationAddress2 xsi:nil="true" />
</q17:DestinationSection>
</q17:DestinationSections>
UPDATE: About NULL values:
Try this
DECLARE #DummyTable TABLE(SomeDescription VARCHAR(500), SomeValue VARCHAR(100));
INSERT INTO #DummyTable VALUES('A real NULL value',NULL)
,('An empty string','')
,('A blank string',' ')
,('Some Text','blah blah');
WITH XMLNAMESPACES('SomeURL' AS q17)
SELECT SomeDescription AS [q17:Description]
,SomeValue AS [q17:Value]
FROM #DummyTable
FOR XML PATH('q17:row'),ELEMENTS XSINIL,ROOT('root');
To get this
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:q17="SomeURL">
<q17:row>
<q17:Description>A real NULL value</q17:Description>
<q17:Value xsi:nil="true" />
</q17:row>
<q17:row>
<q17:Description>An empty string</q17:Description>
<q17:Value></q17:Value>
</q17:row>
<q17:row>
<q17:Description>A blank string</q17:Description>
<q17:Value> </q17:Value>
</q17:row>
<q17:row>
<q17:Description>Some Text</q17:Description>
<q17:Value>blah blah</q17:Value>
</q17:row>
</root>
You can see, that the real NULL is encoded as xsi:nil="true", while the empty string is shown as <q17:Value></q17:Value> (which is exactly the same as <q17:Value />).
Check this answer for some examples about NULL and empty. Check this answer to understand more about text()

Why does the namespace definition appear on the inner element of this query as well as the outer one

Consider the following reasonably simple sql query;
Declare #ad varchar(3) = 'GBR',
#date varchar(10) ,
#time varchar(5),
#refnum varchar(17),
#tm varchar(2) = 'CU';
Set #date = FORMAT(GETUTCDATE(),'yyyy-MM-dd');
Set #time = FORMAT(GETUTCDATE(),'HH-mm');
Set #refnum = 'DOM' + FORMAT(GETUTCDATE(),'yyyyMMdd') + '123456';
WITH XMLNAMESPACES ('http://ec.europa.eu/fisheries/schema/ers/v3' as ers)
Select #ad AS '#AD',
#ad AS '#FR',
#refnum AS '#ON',
#date as '#OD',
#time AS '#OT',
(Select #tm AS '#TM' For xml path('ers:DAT'), TYPE)
For xml path('ers:OPS')
GO
What I was expecting / hoping to get back from this was the following;
<ers:OPS xmlns:ers="http://ec.europa.eu/fisheries/schema/ers/v3" AD="GBR" FR="GBR" ON="DOM20170411123456" OD="2017-04-11" OT="14-47">
<ers:DAT TM="CU" />
</ers:OPS>
Whereas what I in fact got back was ;
<ers:OPS xmlns:ers="http://ec.europa.eu/fisheries/schema/ers/v3" AD="GBR" FR="GBR" ON="DOM20170411123456" OD="2017-04-11" OT="14-47">
<ers:DAT xmlns:ers="http://ec.europa.eu/fisheries/schema/ers/v3" TM="CU" />
</ers:OPS>
My question quite simply is why did I get back what I did and what ought I have done to get back what I had hoped for?
This is a known issue (actually it is a feature, voted to be removed) and there is a Connect item opened since 2007.
You can check it out here.
A possible workaround is described here.

Concatenate XML without type casting to string

I have the following XML generated from various tables in my SQL SERVER database
<XMLData>
...
<Type>1</Type>
...
</XMLData>
AND
<XMLData>
...
<Type>2</Type>
...
</XMLData>
AND
<XMLData>
...
<Type>3</Type>
...
</XMLData>
The final output I need is single combined as follows:
<AllMyData>
<XMLData>
...
<Type>1</Type>
...
</XMLData>
<XMLData>
...
<Type>2</Type>
...
</XMLData>
<XMLData>
...
<Type>3</Type>
...
</XMLData>
<AllMyData>
NOTE - all the independent elements that I am combining have the same tag name.
Thanks in advance for looking this up.
I have the following XML generated from various tables in my SQL
SERVER database
Depends on how you have it but if it is in a XML variable you can do like this.
declare #XML1 xml
declare #XML2 xml
declare #XML3 xml
set #XML1 = '<XMLData><Type>1</Type></XMLData>'
set #XML2 = '<XMLData><Type>2</Type></XMLData>'
set #XML3 = '<XMLData><Type>3</Type></XMLData>'
select #XML1, #XML2, #XML3
for xml path('AllMyData')
I can't comment but can answer so even though I think a comment is more appropriate, I'll expand on what rainabba answered above to add a bit more control. My .Net code needs to know the column name returned so I can't rely on auto-generated names but needed the very tip rainabba provided above otherwise.
This way, the xml can effectively be concatenated into a single row and the resulting column named. You could use this same approach to assign the results to an XML variable and return that from a PROC also.
SELECT (
SELECT XmlData as [*]
FROM
(
SELECT
xmlResult AS [*]
FROM
#XmlRes
WHERE
xmlResult IS NOT NULL
FOR XML PATH(''), TYPE
) as DATA(XmlData)
FOR XML PATH('')
) as [someColumnName]
If you use for xml type, you can combine the XML columns without casting them. For example:
select *
from (
select (
select 1 as Type
for xml path(''), type
)
union all
select (
select 2 as Type
for xml path(''), type
)
union all
select (
select 3 as Type
for xml path(''), type
)
) as Data(XmlData)
for xml path(''), root('AllMyData'), type
This prints:
<AllMyData>
<XmlData>
<Type>1</Type>
</XmlData>
<XmlData>
<Type>2</Type>
</XmlData>
<XmlData>
<Type>3</Type>
</XmlData>
</AllMyData>
As an addendum to Mikael Eriksson's answer - If you have a process where you need to continually add nodes and then want to group that under a single node, this is one way to do it:
declare #XML1 XML
declare #XML2 XML
declare #XML3 XML
declare #XMLSummary XML
set #XML1 = '<XMLData><Type>1</Type></XMLData>'
set #XMLSummary = (SELECT #XMLSummary, #XML1 FOR XML PATH(''))
set #XML2 = '<XMLData><Type>2</Type></XMLData>'
set #XMLSummary = (SELECT #XMLSummary, #XML2 FOR XML PATH(''))
set #XML3 = '<XMLData><Type>3</Type></XMLData>'
set #XMLSummary = (SELECT #XMLSummary, #XML3 FOR XML PATH(''))
SELECT #XMLSummary FOR XML PATH('AllMyData')
I needed to do the same but without knowing how many rows/variables were concerned and without extra schema added so here was my solution. Following this pattern, I can generate as many snippets as I want, combine them, pass them between PROCS or even return them from procs and at any point, wrap them up in containers all without modifying the data or being forced to add XML structure into my data. I use this approach with HTTP end points to provide XML Web services and with another trick that converts XML into JSON, to provide JSON WebServices.
-- SETUP A type (or use this design for a Table Variable) to temporarily store snippets into. The pattern can be repeated to pass/store snippets to build
-- larger elements and those can be further combined following the pattern.
CREATE TYPE [dbo].[XMLRes] AS TABLE(
[xmlResult] [xml] NULL
)
GO
-- Call the following as much as you like to build up all the elements you want included in the larger element
INSERT INTO #XMLRes ( xmlResult )
SELECT
(
SELECT
'foo' '#bar'
FOR XML
PATH('SomeTopLevelElement')
)
-- This is the key to "concatenating" many snippets into a larger element. At the end of this, add " ,ROOT('DocumentRoot') " to wrapp them up in another element even
-- The outer select is a time from user2503764 that controls the output column name
SELECT (
SELECT XmlData as [*]
FROM
(
SELECT
xmlResult AS [*]
FROM
#XmlRes
WHERE
xmlResult IS NOT NULL
FOR XML PATH(''), TYPE
) as DATA(XmlData)
FOR XML PATH('')
) as [someColumnName]
ALTER PROCEDURE usp_fillHDDT #Code int
AS
DECLARE #HD XML,#DT XML;
SET NOCOUNT ON;
select invhdcode, invInvoiceNO,invDate,invCusCode,InvAmount into #HD
from dbo.trnInvoiceHD where invhdcode=#Code
select invdtSlNo No,invdtitemcode ItemCode,invdtitemcode ItemName,
invDtRate Rate,invDtQty Qty,invDtAmount Amount ,'Kg' Unit into #DT from
dbo.trnInvoiceDt where invDtTrncode=#Code
set #HD = (select * from #HD HD FOR XML AUTO,ELEMENTS XSINIL);
set #DT = (select* from #DT DT FOR XML AUTO,ELEMENTS XSINIL);
SELECT CAST ('<OUTPUT>'+ CAST (ISNULL(#HD,'') AS VARCHAR(MAX))+ CAST ( ISNULL(#DT,'') AS VARCHAR(MAX))+ '</OUTPUT>' AS XML)
public String ReplaceSpecialChar(String inStr)
{
inStr = inStr.Replace("&", "&");
inStr = inStr.Replace("<", "<");
inStr = inStr.Replace(">", ">");
inStr = inStr.Replace("'", "'");
inStr = inStr.Replace("\"", """);
return inStr;
}

Test for a specific node value in an XML column including potentially empty nodes

I have an XML column in a SQL Server 2008 database with values like the following simplified examples:
Case 1
<root>
<child>sometimes text here</child>
<otherstuff ..... />
</root>
Case 2
<root>
<child/>
<otherstuff ..... />
</root>
Given a string value, I would like to be able to select rows that have a specific value in the "child" node, including selection of case 2.
So for example, if I have a local variable:
declare #queryText nvarchar(MAX)
select #queryText = 'sometimes text here'
I can select the row that matches case 1 by:
select * from [my_table]
where [my_xml_column].exist('/root/child[text()=sql:variable("#queryText")]') = 1
However, for case 2, where I would expect #queryText = '' or #queryText = NULL to work, neither matches.
As a workaround I can use:
select * from [my_table]
where [my_xml_column].value('(/root/child)[1], 'nvarchar(MAX)') = #queryText
This works, but it leaves me feeling like I'm missing something and using a dirty workaround to test for existence with .value() rather than .exist()... Is there a similar expression I can [and should?] use in .exist() to match either specific text or an empty node? Is there any reason to care beyond readability? I look forward to my impending facepalm when somebody points out whatever blatantly obvious thing I have missed. :)
Calling text() on an empty element results in NULL not an empty string. So, in both cases passing #queryText = '' or #queryText = NULL will never equal NULL. Remember that nothing equals NULL, not even NULL.
See below example that illustrates how to use exist for populated or empty searches.
declare #my_table table (i int, my_xml_column xml)
insert into #my_table
select 1, '<root><child>sometimes text here</child><otherstuff /></root>' union all
select 2, '<root><child/><otherstuff/></root>'
declare #queryText varchar(100) = '';
select *,
[using_text()]=[my_xml_column].value('(/root/child/text())[1]', 'varchar(max)'),
[using_path]=[my_xml_column].value('(/root/child)[1]', 'varchar(max)')
from #my_table
select *
from #my_table
where [my_xml_column].exist('/root/child[.= sql:variable("#queryText")]') = 1

Resources