## ----message = FALSE---------------------------------------------------------- library(dplyr) con <- DBI::dbConnect(RSQLite::SQLite(), ":memory:") flights <- copy_to(con, nycflights13::flights) airports <- copy_to(con, nycflights13::airports) ## ----------------------------------------------------------------------------- flights %>% select(contains("delay")) %>% show_query() flights %>% select(distance, air_time) %>% mutate(speed = distance / (air_time / 60)) %>% show_query() ## ----------------------------------------------------------------------------- flights %>% filter(month == 1, day == 1) %>% show_query() ## ----------------------------------------------------------------------------- flights %>% arrange(carrier, desc(arr_delay)) %>% show_query() ## ----------------------------------------------------------------------------- flights %>% group_by(month, day) %>% summarise(delay = mean(dep_delay, na.rm = TRUE)) %>% show_query()