Hi Roger
This works exactly as it is needed, and even with correct sorting!
Great! I'm not really familiar with the UNION clause but this seems a
great way of using it.
The SQL statement may be somewhat inefficient but is very effective
though. In our database with around 30'000 test records it takes about 4
seconds, we will see how slow/fast it will be in the productive database
with 165'000 records - but it will be worth the waiting!
Thank you very much!
Best wishes: Michael
--
Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis
Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz
T 0041 (0)61 261 55 61 · E m...@adminkuhn.ch · W www.adminkuhn.ch
Am 12.04.21 um 08:50 schrieb Roger Grossmann:
Hi Michael,
an inefficient and quite long running SQL statement for your request might be
the following:
SELECT
s.ser AS series,
s.vol AS volume,
s.biblionumber
FROM
(
SELECT
ExtractValue(a.metadata,'//datafield[@tag="490"][1]/subfield[@code="a"]') AS
ser,
ExtractValue(a.metadata,'//datafield[@tag="490"][1]/subfield[@code="v"]') AS
vol,
a.biblionumber
FROM biblio_metadata a
HAVING ser <> ''
UNION ALL
SELECT
ExtractValue(a.metadata,'//datafield[@tag="490"][2]/subfield[@code="a"]') AS
ser,
ExtractValue(a.metadata,'//datafield[@tag="490"][2]/subfield[@code="v"]') AS
vol,
a.biblionumber
FROM biblio_metadata a
HAVING ser <> ''
UNION ALL
SELECT
ExtractValue(a.metadata,'//datafield[@tag="490"][3]/subfield[@code="a"]') AS
ser,
ExtractValue(a.metadata,'//datafield[@tag="490"][3]/subfield[@code="v"]') AS
vol,
a.biblionumber
FROM biblio_metadata a
HAVING ser <> ''
) AS s
WHERE s.ser = <<Series statement>>
ORDER BY s.vol
Typically there are not many catalog records with more than 3 series.
If you expect more, you can add additional "UNION ALL" clauses with higher
indexes.
The performance depends on the size of the collection.
The statement runs slow due to the full table scans but if it is not a big
collection the speed might be ok.
Best regards,
Roger
--
LMSCloud GmbH
Roger Großmann - Geschäftsführer
Konrad-Zuse-Platz 8 - D-81829 München
e roger.grossm...@lmscloud.de
w www.lmscloud.de
Am 08.04.2021 um 19:23 schrieb Michael Kuhn <m...@adminkuhn.ch>:
Hi
Our library is using Debian GNU/Linux 10 and Koha 20.11.
We are trying to extract the series statement (MARC 490$a) and volume numbers
(MARC 490$v) from the MARCXML data. Some title data records more than one MARC
490 entry. We came up with the following SQL statement:
SELECT biblionumber,
ExtractValue(metadata,'//datafield[@tag="490"]/subfield[@code="a"]'),
ExtractValue(metadata,'//datafield[@tag="490"]/subfield[@code="v"]')
FROM biblio_metadata
WHERE ExtractValue(metadata,'//datafield[@tag="490"]/subfield[@code="a"]') = <<Series
statement>>
ORDER BY ExtractValue(metadata,'//datafield[@tag="490"]/subfield[@code="v"]')
This will only find and sort the records that have just one and only one MARC
490 entry. Even if the given series statement is in the first MARC 490 entry
the record will not show up if the same record has a second MARC 490 entry.
We then changed the SQL statement to:
SELECT biblionumber,
ExtractValue(metadata,'//datafield[@tag="490"][1]/subfield[@code="a"]'),
ExtractValue(metadata,'//datafield[@tag="490"][1]/subfield[@code="v"]')
FROM biblio_metadata
WHERE ExtractValue(metadata,'//datafield[@tag="490"][1]/subfield[@code="a"]') =
<<Series statement>>
ORDER BY ExtractValue(metadata,'//datafield[@tag="490"][1]/subfield[@code="v"]')
At least this will find all records that have the given series statement in the
first MARC 490 entry. But it will (of course) not show or sort the records that
have the given series statement in the second, third, etc MARC 490 entry.
According to
https://wiki.koha-community.org/wiki/SQL_Reports_Library#Query_MARC I
understand that ExtractValue concatenates multiple tags into a single field but
unfortunately I couldn't come up with a solution to our problem...
Using column "seriestitle" from table "biblio" doesn't help because it behaves
the same and there is no possibility to search for the volume number of the series (MARC 490$v).
Can anyone please help us out?
Best wishes: Michael Kuhn
--
Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis
Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz
T 0041 (0)61 261 55 61 · E m...@adminkuhn.ch · W www.adminkuhn.ch
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