Difference between revisions of "Functional Dependencies"
Jump to navigation
Jump to search
(→query) |
|||
| Line 59: | Line 59: | ||
</source> | </source> | ||
| − | [ | + | [https://query.wikidata.org/#%23%20WF%202022-06-08%0A%23%20Singles%20published%20in%202022%0ASELECT%0A%3Fsingle%20%3Flanguage%20%3FcollectionId%20%3Fcollection%20%3FcollectionType%20%3FperformerId%20%3Fperformer%20%3FfollowerCount%20%3FyoutubeVideoId%20%20%28year%28%3FpublicationDate%29%20as%20%3FpublicationYear%29%0AWHERE%0A%7B%0A%20%20%23%20instanceof%0A%20%20%3FsingleId%20wdt%3AP31%20wd%3AQ134556.%20%23%20Must%20be%20of%20a%20single%0A%20%20%3FsingleId%20rdfs%3Alabel%20%3Fsingle.%0A%20%20FILTER%28LANG%28%3Fsingle%29%3D%27en%27%29%0A%0A%20%20%23https%3A//www.wikidata.org/wiki/Property%3AP361%20-%20part%20of%20/%20ist%20Teil%20von%0A%20%20%3FsingleId%20wdt%3AP361%20%3FcollectionId.%0A%20%20%3FcollectionId%20rdfs%3Alabel%20%3Fcollection.%0A%20%20FILTER%28LANG%28%3Fcollection%29%3D%27en%27%29%0A%0A%20%20%23%20https%3A//www.wikidata.org/wiki/Property%3AP407%20language/%20Sprache%20des%20Werkes%0A%20%20%3FsingleId%20wdt%3AP407%20%3FlanguageId.%0A%20%20%3FlanguageId%20rdfs%3Alabel%20%3Flanguage.%0A%20%20FILTER%28LANG%28%3Flanguage%29%3D%27en%27%29%0A%0A%20%20%23%20https%3A//www.wikidata.org/wiki/Property%3AP1651%20YouTube-Video-Kennung%0A%20%20%3FsingleId%20wdt%3AP1651%20%3FyoutubeVideoId.%0A%0A%20%20%3FcollectionId%20wdt%3AP31%20%3FcollectionTypeId.%0A%20%20%3FcollectionTypeId%20rdfs%3Alabel%20%3FcollectionType.%0A%20%20FILTER%28LANG%28%3FcollectionType%29%3D%27en%27%29.%0A%0A%20%20%23%20https%3A//www.wikidata.org/wiki/Property%3AP175%20Performer%20/Interpret%0A%20%20%3FsingleId%20wdt%3AP175%20%3FperformerId.%0A%20%20%3FperformerId%20rdfs%3Alabel%20%3Fperformer%0A%20%20FILTER%28LANG%28%3Fperformer%29%3D%27en%27%29%0A%0A%20%20%23%20https%3A//www.wikidata.org/wiki/Property%3AP8687%20followers%20/%20Follower%0A%20%20%23%7B%0A%20%20%20%20%20%23SELECT%20%28max%28%3FfollowerCount%29%20as%20%3Ffollower%29%0A%20%20%20%20%20%23WHERE%20%7B%0A%20%20%20%20%20%3FperformerId%20wdt%3AP8687%20%3FfollowerCount.%0A%20%20%20%20%20%23%7D%0A%20%20%20%20%20%23GROUP%20BY%20%3FperformerId%0A%20%20%23%7D%0A%20%20%23https%3A//www.wikidata.org/wiki/Property%3AP577%20Publication%20date%20/%20Ver%C3%B6ffentlichungsdatum%0A%20%20%3FsingleId%20wdt%3AP577%20%3FpublicationDate.%0A%20%20FILTER%28year%28%3FpublicationDate%29%20%3D%202022%29.%0A%7D%20ORDER%20BY%20%20DESC%28%3FfollowerCount%29%0ALIMIT%209%0A try it!] |
| + | |||
=== result === | === result === | ||
{| class="wikitable" style="text-align: left;" | {| class="wikitable" style="text-align: left;" | ||
Revision as of 19:24, 8 June 2022
Notation
In Database theory: [math]\{A,B\}\to \{C,D\}[/math] is abbreviated to: [math]AB\to CD[/math]
Example
9 single entries for 2022 sorted by social media followers
query
# WF 2022-06-08
# Singles published in 2022
SELECT
?single ?language ?collectionId ?collection ?collectionType ?performerId ?performer ?followerCount ?youtubeVideoId (year(?publicationDate) as ?publicationYear)
WHERE
{
# instanceof
?singleId wdt:P31 wd:Q134556. # Must be of a single
?singleId rdfs:label ?single.
FILTER(LANG(?single)='en')
#https://www.wikidata.org/wiki/Property:P361 - part of / ist Teil von
?singleId wdt:P361 ?collectionId.
?collectionId rdfs:label ?collection.
FILTER(LANG(?collection)='en')
# https://www.wikidata.org/wiki/Property:P407 language/ Sprache des Werkes
?singleId wdt:P407 ?languageId.
?languageId rdfs:label ?language.
FILTER(LANG(?language)='en')
# https://www.wikidata.org/wiki/Property:P1651 YouTube-Video-Kennung
?singleId wdt:P1651 ?youtubeVideoId.
?collectionId wdt:P31 ?collectionTypeId.
?collectionTypeId rdfs:label ?collectionType.
FILTER(LANG(?collectionType)='en').
# https://www.wikidata.org/wiki/Property:P175 Performer /Interpret
?singleId wdt:P175 ?performerId.
?performerId rdfs:label ?performer
FILTER(LANG(?performer)='en')
# https://www.wikidata.org/wiki/Property:P8687 followers / Follower
#{
#SELECT (max(?followerCount) as ?follower)
#WHERE {
?performerId wdt:P8687 ?followerCount.
#}
#GROUP BY ?performerId
#}
#https://www.wikidata.org/wiki/Property:P577 Publication date / Veröffentlichungsdatum
?singleId wdt:P577 ?publicationDate.
FILTER(year(?publicationDate) = 2022).
} ORDER BY DESC(?followerCount)
LIMIT 9
result
| single | language | collectionId | collection | collectionType | performerId | performer | followerCount | youtubeVideoId | publicationYear |
|---|---|---|---|---|---|---|---|---|---|
| Let Somebody Go | English | http://www.wikidata.org/entity/Q107597380 | Music of the Spheres | album | http://www.wikidata.org/entity/Q83287 | Selena Gomez | 65629044 | EptPhiK_q0E | 2022 |
| As It Was | English | http://www.wikidata.org/entity/Q111343757 | Harry's House | album | http://www.wikidata.org/entity/Q3626966 | Harry Styles | 36156370 | H5v3kku4y6Q | 2022 |
| Let Somebody Go | English | http://www.wikidata.org/entity/Q107597380 | Music of the Spheres | album | http://www.wikidata.org/entity/Q45188 | Coldplay | 23541189 | EptPhiK_q0E | 2022 |
| Bam Bam | English | http://www.wikidata.org/entity/Q56071495 | Camila Cabello singles discography | singles discography | http://www.wikidata.org/entity/Q47447 | Ed Sheeran | 17661915 | -8VfKZCOo_I | 2022 |
| Bam Bam | English | http://www.wikidata.org/entity/Q111083420 | Familia | album | http://www.wikidata.org/entity/Q47447 | Ed Sheeran | 17661915 | -8VfKZCOo_I | 2022 |
| Sacrifice | English | http://www.wikidata.org/entity/Q110400486 | Dawn FM | album | http://www.wikidata.org/entity/Q2121062 | The Weeknd | 15549868 | VafTMsrnSTU | 2022 |
| Out of Time | English | http://www.wikidata.org/entity/Q110400486 | Dawn FM | album | http://www.wikidata.org/entity/Q2121062 | The Weeknd | 15549868 | 2fDzCWNS3ig | 2022 |
| Bam Bam | English | http://www.wikidata.org/entity/Q56071495 | Camila Cabello singles discography | singles discography | http://www.wikidata.org/entity/Q18810940 | Camila Cabello | 12717885 | -8VfKZCOo_I | 2022 |
| Bam Bam | English | http://www.wikidata.org/entity/Q111083420 | Familia | album | http://www.wikidata.org/entity/Q18810940 | Camila Cabello | 12717885 | -8VfKZCOo_I | 2022 |
Links
- https://en.wikipedia.org/wiki/Category:Database_theory
- https://en.wikipedia.org/wiki/Functional_dependency
- https://en.wikipedia.org/wiki/Database_normalization
- https://en.wikipedia.org/wiki/Second_normal_form
- https://en.wikipedia.org/wiki/Third_normal_form
- https://en.wikipedia.org/wiki/Candidate_key
- https://en.wikipedia.org/wiki/Surrogate_key
- https://stackovemahrflow.com/questions/tagged/functional-dependencies