| (: XQuery Join Query :) |
| (: Find the highest recorded temperature (TMAX) for each station for each :) |
| (: day over the year 2002. :) |
| let $station_collection := "ghcnd_quarter_1|ghcnd_quarter_2|ghcnd_quarter_3|ghcnd_quarter_4" |
| for $s in collection($station_collection)/stationCollection/station |
| |
| let $sensor_collection := "ghcnd_quarter_1|ghcnd_quarter_2|ghcnd_quarter_3|ghcnd_quarter_4" |
| for $r in collection($sensor_collection)/dataCollection/data |
| |
| where $s/id eq $r/station |
| and $r/dataType eq "TMAX" |
| and fn:year-from-dateTime(xs:dateTime(fn:data($r/date))) eq 2002 |
| return ($s/displayName, $r/date, $r/value) |
