## ----setup, include = FALSE----------------------------------------------
source("setup/setup.R")

## ----message=FALSE, warning=FALSE----------------------------------------
# library(nycflights13)
# library(dm)

## ------------------------------------------------------------------------
# dm <- dm_nycflights13()

## ------------------------------------------------------------------------
# dm

## ------------------------------------------------------------------------
# dm_draw(dm)

## ------------------------------------------------------------------------
# tbl(dm, "airports")

## ------------------------------------------------------------------------
# filtered_dm <-
#   dm %>%
#   dm_filter(airports = (name == "John F Kennedy Intl"))
# filtered_dm

## ------------------------------------------------------------------------
# rows_per_table <-
#   filtered_dm %>%
#   dm_nrow()
# rows_per_table
# sum(rows_per_table)

## ----echo = FALSE, eval = TRUE-------------------------------------------
sum_nrow <- NA
sum_nrow_filtered <- NA

## ------------------------------------------------------------------------
# sum_nrow <- sum(dm_nrow(dm))
# sum_nrow_filtered <- sum(dm_nrow(dm_apply_filters(filtered_dm)))

## ------------------------------------------------------------------------
# dm %>%
#   dm_filter(flights = (dest == "IAD")) %>%
#   dm_nrow()

## ------------------------------------------------------------------------
# dm_delta_may <-
#   dm %>%
#   dm_filter(
#     airlines = (name == "Delta Air Lines Inc."),
#     airports = (name != "John F Kennedy Intl"),
#     flights = (month == 1)
#   )
# dm_delta_may
# dm_delta_may %>%
#   dm_nrow()

## ------------------------------------------------------------------------
# dm_delta_may$airlines

## ------------------------------------------------------------------------
# dm_delta_may$planes

## ------------------------------------------------------------------------
# dm_delta_may$flights %>%
#   dplyr::count(month)

## ------------------------------------------------------------------------
# airlines_filtered <- filter(airlines, name == "Delta Air Lines Inc.")
# airports_filtered <- filter(airports, name != "John F Kennedy Intl")
# flights %>%
#   semi_join(airlines_filtered, by = "carrier") %>%
#   semi_join(airports_filtered, by = c("origin" = "faa")) %>%
#   filter(month == 5)

## ----warning=FALSE-------------------------------------------------------
# dm %>%
#   dm_select_tbl(flights, airlines, airports) %>%
#   copy_dm_to(dbplyr::src_memdb(), .) %>%
#   dm_filter(
#     airlines = (name == "Delta Air Lines Inc."),
#     airports = (name != "John F Kennedy Intl"),
#     flights = (month == 1)
#   ) %>%
#   dm_get_tables() %>%
#   purrr::map(dbplyr::sql_render)