This is a method for the dplyr group_by() generic. It is translated to
the GROUP BY clause of the SQL query when used with
summarise() and to the PARTITION BY clause of
window functions when used with mutate().
# S3 method for class 'tbl_lazy'
group_by(.data, ..., .add = FALSE, add = deprecated(), .drop = TRUE)A lazy data frame backed by a database query.
<data-masking> Variables, or
functions of variables. Use desc() to sort a variable in descending
order.
When FALSE, the default, group_by() will
override existing groups. To add to the existing groups, use
.add = TRUE.
This argument was previously called add, but that prevented
creating a new grouping variable called add, and conflicts with
our naming conventions.
Deprecated. Please use .add instead.
Not supported by this method.
library(dplyr, warn.conflicts = FALSE)
db <- memdb_frame(g = c(1, 1, 1, 2, 2), x = c(4, 3, 6, 9, 2))
db %>%
group_by(g) %>%
summarise(n()) %>%
show_query()
#> <SQL>
#> SELECT `g`, COUNT(*) AS `n()`
#> FROM `dbplyr_1qeoeBlLyC`
#> GROUP BY `g`
db %>%
group_by(g) %>%
mutate(x2 = x / sum(x, na.rm = TRUE)) %>%
show_query()
#> <SQL>
#> SELECT `dbplyr_1qeoeBlLyC`.*, `x` / SUM(`x`) OVER (PARTITION BY `g`) AS `x2`
#> FROM `dbplyr_1qeoeBlLyC`