如何在Oracle中使用XMLTABLE内部联接三个表

Question

I have a table called XML_INFRASTRUCTURE which has the following design:

COLUMN_NAME  | DATA_TYPE          | NULLABLE
-------------|--------------------|--------
XMLI_ID      | NUMBER(10,0)       | No
FILENAME     | VARCHAR2(255 CHAR) | Yes
LAST_VERSION | DATE               | Yes
XML_RAW      | CLOB               | Yes

In this table I am storing all the XML files I'm receiving through FTP as an XMLTYPE. I use XMLTABLE to get the information out and it all works well, until I start joining tables.

In the XML_INFRASTRUCTURE I have the following data:

XMLI_ID | FILENAME     | LAST_VERSION | XML_RAW
--------|--------------|--------------|--------------------------------
1       | ptcar        | 07-JAN-18    | <?xml version="1.0" encoding="ISO-8859-1"?><cern:ptcars creationDate="2018-03-16T19:35:54" xmlns:cern="http://www.website.com/Infrastructure" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.website.com/Infrastructure ../ns/infrastructure.xsd"><cern:ptcar id="1" validFromDate="1996-06-02" validToDate="2007-12-08" ....>
2       | ptrefColumn  | 07-JAN-18    | <?xml version="1.0" encoding="ISO-8859-1"?><cern:ptrefColumns creationDate="2018-03-20T11:33:21" xmlns:cern="http://www.website.com/Infrastructure" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.website.com/Infrastructure ../ns/infrastructure.xsd"><cern:ptrefColumn id="279" validFromDate="1998-04-01" validToDate="2001-06-11" ....> 
3       | ptref        | 07-JAN-18    | <?xml version="1.0" encoding="ISO-8859-1"?><cern:ptrefs creationDate="2018-03-20T11:33:05" xmlns:cern="http://www.website.com/Infrastructure"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.website.com//Infrastructure ../ns/infrastructure.xsd"><cern:ptref id="232" validFromDate="1998-04-01" validToDate="2001-06-11" ....>

And next I have the following requirements:

Given values: ptrefId and givenDate

select a.longNameFrench , a.longNameDutch
from   ptcar as a, 
       ptrefColumn as b,
       ptref as c
where c.id = ptrefId
and b.id = c.ptrefColumnId
and a.id = b.ptcarId
and a.validFromDate <= givenDate
and a.validToDate >= givenDate
and b.validFromDate <= givenDate
and b.validToDate >= givenDate
and c.validFromDate <= givenDate
and c.validToDate >= givenDate

So knowing this, I tried getting the XML out with XMLTABLE, but I have no idea how to get the join up and running. As you can see I tried chaining the XMLTABLE, but like this it's been running for over an hour now.

SELECT X.LongNameFrench, X.LongNameDutch
FROM XML_Infrastructure,
    XMLTABLE(
        '$d/*:ptcars/*:ptcar'
        PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
        COLUMNS
            Id              VARCHAR2(10)    PATH    '@*:id',
            LongNameFrench  VARCHAR2(60)    PATH    '@*:longNameFrench',
            LongNameDutch   VARCHAR2(60)    PATH    '@*:longNameDutch',
            ValidFromDate   VARCHAR2(10)    PATH    '@*:validFromDate',
            ValidToDate     VARCHAR2(10)    PATH    '@*:validToDate'
    ) AS X,
    XMLTABLE(
        '$d/*:ptrefColumns/*:ptrefColumn'
        PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
        COLUMNS
            Id              VARCHAR2(10)    PATH    '@*:id',
            ValidFromDate   VARCHAR2(10)    PATH    '@*:validFromDate',
            ValidToDate     VARCHAR2(10)    PATH    '@*:validToDate'
    ) AS Y,
    XMLTABLE(
        '$d/*:ptrefs/*:ptref'
        PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
        COLUMNS
            Id              VARCHAR2(10)    PATH    '@*:id',
            ValidFromDate   VARCHAR2(10)    PATH    '@*:validFromDate',
            ValidToDate     VARCHAR2(10)    PATH    '@*:validToDate'
    ) AS Z
WHERE Z.Id = '512'
AND FILENAME = 'ptcar';

Suggestions are very welcome! (Sorry for the overload of information)

Answer 1

You are creating the three XMLTable results X, Y and Z from the same XML document, and that only has the ptcar node - so Y and Z don't find any data (as there are no nodes matching those XPaths).

Given the similarities between the three XML documents, and assuming the ID nodes you've shown are all supposed to be the same value (which isn't the case in your example data), you could use a single XMLTable to extract all of the relevant data from all of the documents:

SELECT X.Name, X.Id, X.ValidFromDate, X.ValidToDate, X.LongNameFrench, X.LongNameDutch
FROM XML_Infrastructure
CROSS JOIN XMLTABLE(
        '$d/*/*'
        PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
        COLUMNS
            Name            VARCHAR2(10)    PATH    './local-name()',
            Id              NUMBER          PATH    '@*:id',
            LongNameFrench  VARCHAR2(60)    PATH    '@*:longNameFrench',
            LongNameDutch   VARCHAR2(60)    PATH    '@*:longNameDutch',
            ValidFromDate   DATE            PATH    '@*:validFromDate',
            ValidToDate     DATE            PATH    '@*:validToDate'
    ) X;

This uses wildcards to get any child node, but you coudl filter that if you have other types you haven't shown. It also adds a name column so you can tell which document each row came from (or you could include the file name if you prefer). It will give null values for the attributes that don't exist in all three.

And then use that in a CTE and join that to itself twice:

WITH cte AS (
  SELECT X.Name, X.Id, X.ValidFromDate, X.ValidToDate, X.LongNameFrench, X.LongNameDutch
  FROM XML_Infrastructure
  CROSS JOIN XMLTABLE(
          '$d/*/*'
          PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
          COLUMNS
              Name            VARCHAR2(30)    PATH    './local-name()',
              Id              NUMBER          PATH    '@*:id',
              LongNameFrench  VARCHAR2(60)    PATH    '@*:longNameFrench',
              LongNameDutch   VARCHAR2(60)    PATH    '@*:longNameDutch',
              ValidFromDate   DATE            PATH    '@*:validFromDate',
              ValidToDate     DATE            PATH    '@*:validToDate'
      ) AS X
)
select a.longNameFrench, a.longNameDutch
from cte a
join cte b on b.id = a.id
join cte c on c.id = b.id
where c.name = 'ptref'
and b.name = 'ptrefColumn'
and a.name = 'ptcar'
and c.id = ptrefId
and a.validFromDate <= givenDate
and a.validToDate >= givenDate
and b.validFromDate <= givenDate
and b.validToDate >= givenDate
and c.validFromDate <= givenDate
and c.validToDate >= givenDate;

This is somewhat similar to creating views of the queries for each document type and then joining those, but without needing any new permanent objects.

With your partial sample data in another CTE, and setting all the IDs to 512 and adding the missing names in ptcar :

with XML_INFRASTRUCTURE (XMLI_ID, FILENAME, LAST_VERSION, XML_RAW) as (
  select cast (1 as number(2,0)), cast('ptcar' as varchar2(255)), date '2018-01-07', to_clob('<?xml version="1.0" encoding="ISO-8859-1"?>
<cern:ptcars creationDate="2018-03-16T19:35:54" xmlns:cern="http://www.website.com/Infrastructure" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.website.com/Infrastructure ../ns/infrastructure.xsd">
 <cern:ptcar id="512" validFromDate="1996-06-02" validToDate="2007-12-08" longNameFrench="Jean Dupont" longNameDutch="Jan Jansen"/>
</cern:ptcars>') from dual
  union all select 2, 'ptrefColumn', date '2018-01-07', to_clob('<?xml version="1.0" encoding="ISO-8859-1"?>
<cern:ptrefColumns creationDate="2018-03-20T11:33:21" xmlns:cern="http://www.website.com/Infrastructure" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.website.com/Infrastructure ../ns/infrastructure.xsd">
 <cern:ptrefColumn id="512" validFromDate="1998-04-01" validToDate="2001-06-11" />
</cern:ptrefColumns>') from dual
  union all select 3, 'ptref', date '2018-01-07', to_clob('<?xml version="1.0" encoding="ISO-8859-1"?>
<cern:ptrefs creationDate="2018-03-20T11:33:05" xmlns:cern="http://www.website.com/Infrastructure" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.website.com//Infrastructure ../ns/infrastructure.xsd">
 <cern:ptref id="512" validFromDate="1998-04-01" validToDate="2001-06-11" />
</cern:ptrefs>') from dual
),
cte AS (
  SELECT X.Name, X.Id, X.ValidFromDate, X.ValidToDate, X.LongNameFrench, X.LongNameDutch
  FROM XML_Infrastructure
  CROSS JOIN XMLTABLE(
          '$d/*/*'
          PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
          COLUMNS
              Name            VARCHAR2(30)    PATH    './local-name()',
              Id              NUMBER          PATH    '@*:id',
              LongNameFrench  VARCHAR2(60)    PATH    '@*:longNameFrench',
              LongNameDutch   VARCHAR2(60)    PATH    '@*:longNameDutch',
              ValidFromDate   DATE            PATH    '@*:validFromDate',
              ValidToDate     DATE            PATH    '@*:validToDate'
      ) AS X
)
select a.longNameFrench, a.longNameDutch
from cte a
join cte b on b.id = a.id
join cte c on c.id = b.id
where c.name = 'ptref'
and b.name = 'ptrefColumn'
and a.name = 'ptcar'
and c.id = 512
and a.validFromDate <= date '2001-01-01'
and a.validToDate >= date '2001-01-01'
and b.validFromDate <= date '2001-01-01'
and b.validToDate >= date '2001-01-01'
and c.validFromDate <= date '2001-01-01'
and c.validToDate >= date '2001-01-01';

gives

LONGNAMEFRENCH                                               LONGNAMEDUTCH                                               
------------------------------------------------------------ ------------------------------------------------------------
Jean Dupont                                                  Jan Jansen                                                  

Answer 2

Make a select (or create views) like this:

CREATE VIEW ptcar AS
SELECT Id, LongNameFrench, LongNameDutch,
    TO_DATE(x.ValidFromDate, 'YYYY-MM-DD') as ValidFromDate,
    ...
FROM XML_Infrastructure,
    XMLTABLE(
        '$d/*:ptcars/*:ptcar'
        PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
        COLUMNS
            Id              VARCHAR2(10)    PATH    '@*:id',
            LongNameFrench  VARCHAR2(60)    PATH    '@*:longNameFrench',
            LongNameDutch   VARCHAR2(60)    PATH    '@*:longNameDutch',
            ValidFromDate   VARCHAR2(10)    PATH    '@*:validFromDate',
            ValidToDate     VARCHAR2(10)    PATH    '@*:validToDate'
    ) as x;

CREATE VIEW ptrefColumn AS
SELECT Id,
    TO_DATE(x.ValidFromDate, 'YYYY-MM-DD') as ValidFromDate,
    ...
FROM XML_Infrastructure,
XMLTABLE(
    '$d/*:ptrefColumns/*:ptrefColumn'
    PASSING XMLTYPE(XML_Infrastructure.XML_RAW) as "d"
    COLUMNS
        Id              VARCHAR2(10)    PATH    '@*:id',
        ValidFromDate   VARCHAR2(10)    PATH    '@*:validFromDate',
        ValidToDate     VARCHAR2(10)    PATH    '@*:validToDate'
) as x

Afterwards you can join them directly as given in your question.

NB, why do you store XML_RAW as CLOB rather than XMLTYPE ?