Creates an example dm object from the tables in nycflights13, along with the references. See nycflights13::flights for a description of the data. As described in nycflights13::planes, the relationship between the flights table and the planes tables is "weak", it does not satisfy data integrity constraints.

dm_nycflights13(cycle = FALSE, color = TRUE, subset = TRUE, compound = TRUE)

Arguments

cycle

Boolean. If FALSE (default), only one foreign key relation (from flights$origin to airports$faa) between the flights table and the airports table is established. If TRUE, a dm object with a double reference between those tables will be produced.

color

Boolean, if TRUE (default), the resulting dm object will have colors assigned to different tables for visualization with dm_draw().

subset

Boolean, if TRUE (default), the flights table is reduced to flights with column day equal to 10.

compound

Boolean, if FALSE, no link will be established between tables flights and weather, because this requires compound keys.

Value

A dm object consisting of nycflights13 tables, complete with primary and foreign keys and optionally colored.

Examples

dm_nycflights13() %>%
  dm_draw()
%0

airlinesairlinescarrierairportsairportsfaaflightsflightscarriertailnumoriginorigin, time_hourflights:carrier->airlines:carrierflights:origin->airports:faaplanesplanestailnumflights:tailnum->planes:tailnumweatherweatherorigin, time_hourflights:origin, time_hour->weather:origin, time_hour