Parsing XML data with Postgres - postgresql

Question

PostgreSQL 9.2.4
I apologize if I added a duplicate topic, but I can't seem to figure it out (yet). I'd like to parse XML data which is stored in postgres table.
For example:
select program_information.description FROM program_information WHERE id = 8768787;
gives me output like:
<?xml version="1.0"?>
<ProgramInformation>
<BasicDescription>
<Title type="original">Zla smrt</Title>
<Synopsis length="short">Pet prijateljev, starih nekaj čez dvajset let, v samotni koči najde Knjigo mrtvih. S posnetka, ki so ga napravili arheologi, izvedo, da je bilo starodavno besedilo odkrito med kandarijskimi ruševinami sumerske civilizacije.</Synopsis>
<Keyword type="secondary"></Keyword>
<ParentalGuidance>
<mpeg7:ParentalRating href="rn:mpeg:MPAAParentalRatingCS:PG">
<mpeg7:Name>PG</mpeg7:Name>
</mpeg7:ParentalRating>
</ParentalGuidance>
<CreditsList>
<CreditsItem role="urn:tva:metadata:TVARoleCS:ACTOR">
<PersonName>
<mpeg7:GivenName>Bruce</mpeg7:GivenName>
<mpeg7:FamilyName>Campbell</mpeg7:FamilyName>
</PersonName>
</CreditsItem>
<CreditsItem role="urn:tva:metadata:TVARoleCS:ACTOR">
<PersonName>
<mpeg7:GivenName>Ellen</mpeg7:GivenName>
<mpeg7:FamilyName>Sandweiss</mpeg7:FamilyName>
</PersonName>
</CreditsItem>
<CreditsItem role="urn:tva:metadata:TVARoleCS:ACTOR">
<PersonName>
<mpeg7:GivenName>Betsy</mpeg7:GivenName>
<mpeg7:FamilyName>Baker</mpeg7:FamilyName>
</PersonName>
</CreditsItem>
<CreditsItem role="urn:tva:metadata:TVARoleCS:DIRECTOR">
<PersonName>
<mpeg7:GivenName>Sam</mpeg7:GivenName>
<mpeg7:FamilyName>Raimi</mpeg7:FamilyName>
</PersonName>
</CreditsItem>
</CreditsList>
<ReleaseInformation>
<ReleaseDate>
<Year>1981</Year>
</ReleaseDate>
</ReleaseInformation>
</BasicDescription>
<AVAttributes>
<AudioAttributes>
<NumOfChannels>2</NumOfChannels>
</AudioAttributes>
</AVAttributes>
</ProgramInformation>
So what I'd like is a parsed output of that output in separate columns (title, synopsis, ratings, actors, etc.)
So what I'd like is an output like
+----------+-------------+----------------+
| Title | Synopsis | ParentalRating |
+----------+-------------+----------------+
| my title | some descr | rating |
+----------+-------------+----------------+
I've tried with xpath but so far a dead end... :/
Can anyone guide me to correct query? Thank you!
M

Answer 1

Your XML document misses a namespace declaration. Is it supposed to be like that? I manually added a namespace at <ProgramInformation> and it worked ..
<ProgramInformation xmlns:mpeg7="http://mpeg7.io">
.. with the following query:
SELECT
XPATH('//BasicDescription/Title/text()', t.xml) AS title,
XPATH('//BasicDescription/Synopsis/text()', t.xml) AS synopsis,
XPATH('//mpeg7:ParentalRating/mpeg7:Name/text()', t.xml,ARRAY[ARRAY['mpeg7', 'http://mpeg4.io']]) AS parentalRating
FROM t;
title | synopsis | parentalrating
--------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------
{"Zla smrt"} | {"Pet prijateljev, starih nekaj čez dvajset let, v samotni koči najde Knjigo mrtvih. S posnetka, ki so ga napravili arheologi, izvedo, da je bilo starodavno besedilo odkrito med kandarijskimi ruševinami sumerske civilizacije."} | {PG}
(1 Zeile)