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## ---- include = FALSE---------------------------------------------------------
knitr::opts_chunk$set(
collapse = TRUE,
comment = "#>"
)
## ----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 <- tbl_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())
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