## ----------------------------------------------------------------------------- knitr::opts_chunk$set(collapse = TRUE, comment = "#>") options(tibble.print_min = 6L, tibble.print_max = 6L, digits = 3) ## ----setup, message = FALSE--------------------------------------------------- library(dplyr) library(dbplyr) ## ----------------------------------------------------------------------------- mf <- memdb_frame(g = c(1, 1, 2, 2, 2), x = 1:5, y = 5:1) mf mf |> group_by(g) |> summarise_all(mean, na.rm = TRUE) ## ----------------------------------------------------------------------------- mtcars_db <- copy_to(memdb(), mtcars) mtcars_db |> group_by(cyl) |> summarise(n = n()) |> show_query() ## ----------------------------------------------------------------------------- x <- c("abc", "def", "ghif") lazy_frame(x = x, con = simulate_postgres()) |> head(5) |> show_query() lazy_frame(x = x, con = simulate_mssql()) |> head(5) |> show_query() ## ----------------------------------------------------------------------------- translate_sql(substr(x, 1, 2), con = simulate_postgres()) translate_sql(substr(x, 1, 2), con = simulate_sqlite())