Use SQL Server modify('insert') to append data to xml column - sql

Question

Consider the following situation. I have the following table
CREATE TABLE [dbo].[GoldenEgg]
(
rowIndex int NOT NULL IDENTITY(1,1),
AccountNumber varchar(256) NULL,
SubscriptionID int NOT NULL,
SubscriptionData_XML xml NULL,
SubscriptionData_AFTER_XML NULL
CONSTRAINT [PK_GoldenEgg]
PRIMARY KEY CLUSTERED ([rowIndex] ASC)
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON,
ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GoldenEgg sample data:
SubscriptionData_XML data for SubscriptionID 6070:
<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
</Value>
</Item>
</NVPList>
I want to append all account numbers for each SubscriptionID to the already existing xml <Value> node in the SubscriptionData_XML column and I do not want to add account numbers that already exist in the xml.
So for SubscriptionID 6070 account number 39448474 should only be listed once in the xml like so:
<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
<ValueItem>56936495</ValueItem>
<ValueItem>70660044</ValueItem>
<ValueItem>41447395</ValueItem>
</Value>
</Item>
</NVPList>

Answer 1

If there are not other nodes within your XML you might choose the FLWOR-query.
Some hints:
first I create a mock-up table and fill it with data
I use and updateable CTE to collect the data
I use a FOR XML-sub-select without a namespace to build the <Value> node wihtout bothering about already existing IDs in your actual XML
I use a FLWOR-query() to build up the full XML out of the just created Value-node
As this CTE is updateable, I can use it directly for the UPDATE
The final SELECT * FROM #tbl shows to you, that all AFTER_XML are filled
Try this:
DECLARE #tbl TABLE(rowIndex INT IDENTITY,AccountNumber INT,SubscriptionID INT, SubscriptionData_XML XML,SubscriptionData_AFTER_XML XML);
INSERT INTO #tbl VALUES
(1111,6070,N'<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
</Value>
</Item>
</NVPList>',NULL)
,(2222,6070,NULL,NULL)
,(3333,6070,NULL,NULL)
,(4444,6070,NULL,NULL)
,(5555,6071,N'<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
</Value>
</Item>
</NVPList>',NULL)
,(6666,6071,NULL,NULL)
,(7777,6071,NULL,NULL)
,(8888,6071,NULL,NULL);
--Here starts the updateable CTE
WITH UpdateableCTE AS
(
SELECT t1.rowIndex
,t1.SubscriptionData_AFTER_XML
,(
SELECT t2.AccountNumber AS ValueItem
FROM #tbl AS t2
WHERE t2.SubscriptionID=t1.SubscriptionID
FOR XML PATH(''),ROOT('Value'),TYPE
).query
(N'declare default element namespace "http://www.whatevernamspace.com/v1";
let $nd:=/*:Value
return
<NVPList>
<Item>
<Name>{sql:column("XmlName")}</Name>
<Value>
{
for $vi in $nd/*:ValueItem
return <ValueItem>{$vi/text()}</ValueItem>
}
</Value>
</Item>
</NVPList>
'
) AS NewXML
FROM #tbl AS t1
CROSS APPLY( SELECT t1.SubscriptionData_XML.value('(//*:Name)[1]','nvarchar(max)') AS XmlName) AS x
WHERE SubscriptionData_XML IS NOT NULL
)
--The UPDATE statement
UPDATE UpdateableCTE SET SubscriptionData_AFTER_XML=NewXML
FROM UpdateableCTE;
--The SELECT to check the success
SELECT * FROM #tbl

Answer 2

I was able to accomplish this task with a sql UPDATE statement using the xml modify() method and without using any loops. Here is a breakdown of the solution:
1) I had to get all the AccountNumbers for the SubscriptionID and format them in
into xml <ValueItem> nodes.
SQL QUERY 1:
SELECT
ge.SubscriptionID,
CAST((SELECT DISTINCT ValueItem = ISNULL(ge2.AccountNumber,'')
FROM dbo.GoldenEgg ge2
WHERE ge2.SubscriptionID = ge.SubscriptionID
FOR XML PATH('')) AS xml) AS AccountNumberXml
FROM dbo.GoldenEgg ge
WHERE ge.SubscriptionData_XML IS NOT NULL
SQL QUERY 1 RESULT:
SQL QUERY 1 XML RESULT (SubscriptionID 6070):
<ValueItem>39448474</ValueItem>
<ValueItem>41447395</ValueItem>
<ValueItem>56936495</ValueItem>
<ValueItem>70660044</ValueItem>
2) Now that I have the AccountNumbers in a single value, I can now use the xml modify() method and insert the AccountNumberXml value into the last position of the <Value> xml node. I will do this using an UPDATE statement with INNER JOIN. Also note that I initally set SubscriptionData_AFTER_XML equal to SubscriptionData_XML before doing anything.
SQL QUERY 2:
UPDATE ge
SET SubscriptionData_AFTER_XML.modify
('declare default element namespace "http://www.whatevernamspace.com/v1";
insert sql:column("t1.AccountNumberXml") as last into (/NVPList/Item/Value)[1]')
FROM dbo.GoldenEgg ge
INNER JOIN (SELECT
ge2.SubscriptionID,
CAST((SELECT DISTINCT ValueItem = ISNULL(ge1.AccountNumber,'')
FROM dbo.GoldenEgg ge1
WHERE ge1.SubscriptionID = ge2.SubscriptionID
FOR XML PATH('')) AS xml) as AccountNumberXml
FROM dbo.GoldenEgg ge2
WHERE ge2.SubscriptionData_AFTER_XML IS NOT NULL) t1 ON t1.SubscriptionID = ge.SubscriptionID
WHERE ge.SubscriptionData_AFTER_XML IS NOT NULL
SQL QUERY 2 RESULT:
SQL QUERY 2 XML RESULT (SubscriptionID 6070 SubscriptionData_AFTER_XML column):
<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
<ValueItem xmlns="">39448474</ValueItem>
<ValueItem xmlns="">41447395</ValueItem>
<ValueItem xmlns="">56936495</ValueItem>
<ValueItem xmlns="">70660044</ValueItem>
</Value>
</Item>
</NVPList>
As you may see there are now two problems with the final xml result in the SubscriptionData_AFTER_XML column.
Problem 1
For subscriptionID 6070 AccountNumber 39448474 is being repeated in the <ValueItem> node list, which I do not want. To fix this I have to query the current AccountNumber values in the xml and exclude those AccountNumbers from the previous INNER JOIN
SQL QUERY 3:
This query will give me a result set with all the current AccountNumbers in the SubscriptionData_XML column, which I can then use to exclude these AccountNumbers from the SQL QUERY 1 result set
SELECT SubscriptionID, t.c.value('.', 'varchar(MAX)') as CurrentValueItems
FROM dbo.GoldenEgg
CROSS APPLY SubscriptionData_XML.nodes('declare default element namespace "http://www.whatevernamspace.com/v1";
/NVPList/Item/Value/ValueItem') as t(c)
WHERE SubscriptionData_XML IS NOT NULL
SQL QUERY 3 RESULT:
Now putting it all together to get the correct final result
SQL QUERY 4:
UPDATE ge
SET SubscriptionData_AFTER_XML.modify
('declare default element namespace "http://www.whatevernamspace.com/v1";
insert sql:column("t1.AccountNumberXml") as last into (/NVPList/Item/Value)[1]')
FROM dbo.GoldenEgg ge
INNER JOIN (SELECT
ge2.SubscriptionID,
CAST((SELECT DISTINCT ValueItem = ISNULL(ge1.AccountNumber,'')
FROM dbo.GoldenEgg ge1
--make sure we are not inserting AccountNumbers that already exists in the subscription data
WHERE ge1.AccountNumber NOT IN (SELECT t.c.value('.', 'varchar(MAX)') as CurrentValueItems
FROM dbo.GoldenEgg
CROSS APPLY SubscriptionData_XML.nodes('declare default element namespace "http://www.whatevernamspace.com/v1";
/NVPList/Item/Value/ValueItem') as t(c)
WHERE SubscriptionData_XML IS NOT NULL
AND SubscriptionID = ge2.SubscriptionID)
AND ge1.SubscriptionID = ge2.SubscriptionID
FOR XML PATH('')) AS xml) as AccountNumberXml
FROM dbo.GoldenEgg ge2
WHERE ge2.SubscriptionData_AFTER_XML IS NOT NULL) t1 ON t1.SubscriptionID = ge.SubscriptionID
WHERE ge.SubscriptionData_AFTER_XML IS NOT NULL
SQL QUERY 4 XML RESULT (SubscriptionID 6070 SubscriptionData_AFTER_XML column):
As you can see AccountNumber 39448474 is now only listed once in the xml
<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
<ValueItem xmlns="">41447395</ValueItem>
<ValueItem xmlns="">56936495</ValueItem>
<ValueItem xmlns="">70660044</ValueItem>
</Value>
</Item>
</NVPList>
Problem 2
When the with AccountNumber node list is inserted, it is being inserted with an empty xmlns="" namespace. This is query I used to remove the empty xmlns="" namespace.
SQL QUERY 5:
UPDATE dbo.GoldenEgg
SET SubscriptionData_AFTER_XML = CONVERT(XML, REPLACE(CONVERT(NVARCHAR(MAX), SubscriptionData_AFTER_XML), N'xmlns=""',''))
WHERE SubscriptionData_AFTER_XML IS NOT NULL
SQL QUERY 5 XML RESULT (SubscriptionID 6070):
<NVPList xmlns="http://www.whatevernamspace.com/v1" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Item>
<Name>AccountNumbers</Name>
<Value>
<ValueItem>39448474</ValueItem>
<ValueItem>41447395</ValueItem>
<ValueItem>56936495</ValueItem>
<ValueItem>70660044</ValueItem>
</Value>
</Item>
</NVPList>
I hope this helps anyone who may need to do something similar