Data Query Language

The Data Query Language is a simple language to query summarized (hourly, daily...) meteorological data from stations. The structure of a query is:

$fieldA[, $fieldB ...] from $table $interval_expr [if $condition_expr]

Summarized fields

Summarized fields are directly related to data emitted by the station with a simple aggregation applied afterwards. The complete list of fields is:

Field	Description	Type
`t.in.max.dt`	Maximum interior temperature (Date)	datetime
`t.in.min.dt`	Minimum interior temperature (Date)	datetime
`h.in.max.dt`	Maximum interior humidity (Date)	datetime
`h.in.min.dt`	Minimum interior humidity (Date)	datetime
`rate.max.dt`	Maximum rain rate (Date)	datetime
`dew.max.dt`	Maximum dewpoint (Date)	datetime
`dew.min.dt`	Minimum dewpoint (Date)	datetime
`bar.max.dt`	Maximum barometer (Date)	datetime
`bar.min.dt`	Minimum barometer (Date)	datetime
`wc.min.dt`	Minimum windchill (Date)	datetime
`hi.max.dt`	Maximum heat index (Date)	datetime
`t.max.dt`	Maximum temperature (Date)	datetime
`t.min.dt`	Minimum temperature (Date)	datetime
`t.in.max`	Maximum interior temperature	double
`t.in.avg`	Average interior temperature	double
`t.in.min`	Minimum interior temperature	double
`h.max.dt`	Maximum humidity (Date)	datetime
`h.min.dt`	Minimum humidity (Date)	datetime
`h.in.max`	Maximum interior humidity	double
`h.in.avg`	Average interior humidity	double
`h.in.min`	Minimum interior humidity	double
`rate.max`	Maximum rain rate	double
`dew.max`	Maximum dewpoint	double
`dew.avg`	Average dewpoint	double
`dew.min`	Minimum dewpoint	double
`bar.max`	Maximum barometer	double
`bar.avg`	Average barometer	double
`bar.min`	Minimum barometer	double
`gust.dt`	Maximum wind gust (Date)	datetime
`t.ampl`	Temperature amplitude (T.max-T.min)	double
`wc.avg`	Average windchill	double
`wc.min`	Minimum windchill	double
`hi.max`	Maximum heat index	double
`hi.avg`	Average heat index	double
`t.max`	Maximum temperature	double
`t.avg`	Average temperature	double
`t.min`	Minimum temperature	double
`h.max`	Maximum humidity	double
`h.avg`	Average humidity	double
`h.min`	Minimum humidity	double
`wind`	Average wind speed	double
`gust`	Maximum wind gust	double
`rain`	Total rain	double
`rate`	Average rain rate	double

Tables

All the tables contain the same kind of information, but summarized into different date ranges:

Table
`hourly`
`daily`
`monthly`

Interval expression

An interval expression defines the range of time the data will be queried. There are several predefined intervals:

last $NUMBER hours
last $NUMBER days
last $NUMBER weeks
last $NUMBER months
last year
last $NUMBER years
last winter: last finished meteorological winter (3 months, from december to february)
$month: a full month using strings (january, february...) of the current year
$month $year: a full month using strings (january, february...) and full year (2024)

Condition expression

A condition enables the filtering of the data in the given interval. The structure of a condition is the following:

$field $operator $value

$value: the name of double field already shown previously
operator: a binary boolean operator. The compatible ones are: >=, >, <, <=
$value: the numeric (double) value being compared with the field using the given boolean operator