Apply previously shredded xml values to subsequent elements

Question

I have the following xml. How can I keep the value of each cond-id and apply it to each subsequent price-container element before encountering a new cond-id with out creating duplicate rows.

I have tried several things and this is the closest I have come.

declare @xml xml =
'-<module mod-id="333">
<title>NNN NNNNN NNNNN</title>
-<data-code>
<code-id>333-004</code-id>
<description>XXX XXX  XXXXXXXX XXX X  XXXXXXXXXXXXXXXX</description>
-<applic>
-<p32>

-<condition cond-id="o-000008888">
<ctext> NNN NNNNNNNNN NN NNNNN NNNNNNNNN NN</ctext>
</condition>
-<m234 domicile="all" ver-start="4.40" target-ver="4.40" vocation="all">
-<value>
<price-container pwdb-id="p-000121212">267</price-container>
<weight-container pwdb-id="w-000676767">0/40</weight-container>
</value>
</m234>
</p32>
</applic>
</data-code>

-<data-code>
<code-id>333-005</code-id>
<description>NNNNNNNNNNNNN NNNNNNNNNN NNNNN N NNNN N NNN NNNNNNNN</description>
-<applic>
-<p32>

-<condition cond-id="o-000002222">
<ctext> NNNNNN NNNNN XXXX NNNN XXXX NNNNNNNN XXXXXXXX </ctext>
</condition>
-<m234 domicile="all" ver-start="4.40" target-ver="4.40" vocation="all">
-<value>
<price-container pwdb-id="p-000123456">N/C</price-container>
<weight-container pwdb-id="w-000234567">0/0</weight-container>
</value>
</m234>

-<condition cond-id="o-000033333">
<ctext> Price with DC 622-005 , DC 622-197, , and DC 622-292 </ctext>
</condition>
-<m234 domicile="all" ver-start="4.80" target-ver="4.80" vocation="all">
-<value>
<price-container pwdb-id="p-000456789">99999</price-container>
<weight-container pwdb-id="w-000789012">0/0</weight-container>
</value>
</m234>

</p32>
</applic>
</data-code>
</module>'


select 
price.value('(../../../../../code-id)[1]', 'varchar(50)') as data_code,
price.value('@pwdb-id', 'varchar(50)') as pwdb_id,
price.value('(text())[1]', 'varchar(50)') as text,
cond.value('(@cond-id) [1]', 'varchar(50)') as cond_id
from @xml.nodes('/module/data-code/applic/p32') as Xtble(datanode)
cross apply Xtble.datanode.nodes('m234/value/price-container') as Xtble2(price)
outer apply Xtble.datanode.nodes('condition') as Xtble3(cond)

This is what I am getting

data_code   pwdb_id         text    cond_id
333-004     p-000121212     267     o-000008888
333-005     p-000123456     N/C     o-000002222
333-005     p-000456789     99999   o-000002222
333-005     p-000123456     N/C     o-000033333
333-005     p-000456789     99999   o-000033333

This is what I want

data_code   pwdb_id         text    cond_id
333-004     p-000121212     267     o-000008888
333-005     p-000123456     N/C     o-000002222
333-005     p-000456789     99999   o-000033333

Answer 1

In such cases I prefere to use CROSS APPLY to calculate a tally-on-the-fly as derived set and use sql:column() to read position-related nodes via position predicate.

declare @xml xml =
N'<module mod-id="333">
  <title>NNN NNNNN NNNNN</title>
  <data-code>
    <code-id>333-004</code-id>
    <description>XXX XXX  XXXXXXXX XXX X  XXXXXXXXXXXXXXXX</description>
    <applic>
      <p32>
        <condition cond-id="o-000008888">
          <ctext> NNN NNNNNNNNN NN NNNNN NNNNNNNNN NN</ctext>
        </condition>
        <m234 domicile="all" ver-start="4.40" target-ver="4.40" vocation="all">
          <value>
            <price-container pwdb-id="p-000121212">267</price-container>
            <weight-container pwdb-id="w-000676767">0/40</weight-container>
          </value>
        </m234>
      </p32>
    </applic>
  </data-code>
  <data-code>
    <code-id>333-005</code-id>
    <description>NNNNNNNNNNNNN NNNNNNNNNN NNNNN N NNNN N NNN NNNNNNNN</description>
    <applic>
      <p32>
        <condition cond-id="o-000002222">
          <ctext> NNNNNN NNNNN XXXX NNNN XXXX NNNNNNNN XXXXXXXX </ctext>
        </condition>
        <m234 domicile="all" ver-start="4.40" target-ver="4.40" vocation="all">
          <value>
            <price-container pwdb-id="p-000123456">N/C</price-container>
            <weight-container pwdb-id="w-000234567">0/0</weight-container>
          </value>
        </m234>
        <condition cond-id="o-000033333">
          <ctext> Price with DC 622-005 , DC 622-197, , and DC 622-292 </ctext>
        </condition>
        <m234 domicile="all" ver-start="4.80" target-ver="4.80" vocation="all">
          <value>
            <price-container pwdb-id="p-000456789">99999</price-container>
            <weight-container pwdb-id="w-000789012">0/0</weight-container>
          </value>
        </m234>
      </p32>
    </applic>
  </data-code>
</module>';

--the query

SELECT A.dc.value('(code-id/text())[1]','nvarchar(100)') AS data_code
      ,A.dc.value('(applic/p32/m234[sql:column("Nmbr")]/value/price-container/@pwdb-id)[1]','nvarchar(100)') AS pwdb_id
      ,A.dc.value('(applic/p32/m234[sql:column("Nmbr")]/value/price-container/text())[1]','nvarchar(100)') AS [text]
      ,A.dc.value('(applic/p32/condition[sql:column("Nmbr")]/@cond-id)[1]','nvarchar(100)') AS cond_id
FROM @xml.nodes('/module/data-code') A(dc)
CROSS APPLY(SELECT TOP(A.dc.value('count(applic/p32/condition)','int')) ROW_NUMBER() OVER(ORDER BY(SELECT NULL)) FROM master..spt_values) B(Nmbr);

The reslt

data_code   pwdb_id     text    cond_id
333-004     p-000121212 267     o-000008888
333-005     p-000123456 N/C     o-000002222
333-005     p-000456789 99999   o-000033333

The idea in short:

We use .nodes() to get the repeated <data-code> nodes.
Now we use a trick with CROSS APPLY: This will return a list of 1 to n as derived set, where n is the count of <condition> nodes.
As you can see, I can use the numbers (returned by the APPLY) in sql:column("Nmbr"). This will pick the condition[1] together with m234[1] and condition[2] together with m234[2] and so on.

Any usage of backward navigation ../ and the suggested << tend to be very slow...

Answer 2

You can calculate the row numbers for each CROSS APPLY and correlate them, like this:

SELECT x1.data_code, x1.pwdb_id, x1.text, x2.cond_id
FROM @xml.nodes('/module/data-code/applic/p32') as Xtble(datanode)
CROSS APPLY (
    SELECT ROW_NUMBER() OVER (ORDER BY price) AS RowNum1, 
        price.value('(../../../../../code-id)[1]', 'varchar(50)') as data_code,
        price.value('@pwdb-id', 'varchar(50)') as pwdb_id,
        price.value('(text())[1]', 'varchar(50)') as text
    FROM Xtble.datanode.nodes('m234/value/price-container') as Xtble2(price)
) x1
CROSS APPLY (
    SELECT ROW_NUMBER() OVER (ORDER BY cond) AS RowNum2, 
        cond.value('(@cond-id) [1]', 'varchar(50)') as cond_id
    FROM Xtble.datanode.nodes('condition') as Xtble3(cond)
) x2
WHERE x1.RowNum1=x2.RowNum2