summarise.tbl_lazy {dbplyr}R Documentation

Summarise each group to one row

Description

This is a method for the dplyr summarise() generic. It generates the SELECT clause of the SQL query, and generally needs to be combined with group_by().

Usage

## S3 method for class 'tbl_lazy'
summarise(.data, ...)

Arguments

.data

A lazy data frame backed by a database query.

...

<data-masking> Variables, or functions or variables. Use desc() to sort a variable in descending order.

Value

Another tbl_lazy. Use show_query() to see the generated query, and use collect() to execute the query and return data to R.

Examples

library(dplyr, warn.conflicts = FALSE)

db <- memdb_frame(g = c(1, 1, 1, 2, 2), x = c(4, 3, 6, 9, 2))
db %>%
  summarise(n()) %>%
  show_query()

db %>%
  group_by(g) %>%
  summarise(n()) %>%
  show_query()

[Package dbplyr version 2.0.0 Index]