The following query returns data for the first three tributaries of Lake Geneva but not others, even though there is data available.
SELECT ?trib ?tribLabel ?length ?elevation ?area ?discharge
WHERE
{
wd:Q6403 wdt:P200 ?trib .
OPTIONAL {
?trib wdt:P2043 ?length .
?trib wdt:P2053 ?area .
?trib wdt:P2044 ?elevation .
?trib wdt:P2225 ?discharge .
}
SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
} ORDER BY DESC(?length) ?tribLabel
LIMIT 50
For tributary 'Eau Floride' (and others) the data exists on the wikidata entry page but is not showing up via this query. Why not? See the images below...