nest_join()
returns all rows and columns in x
with a new nested-df column
that contains all matches from y
. When there is no match, the list column
is a 0-row tibble.
nest_join(x, y, by = NULL, copy = FALSE, keep = FALSE, name = NULL, ...)# S3 method for data.frame
nest_join(x, y, by = NULL, copy = FALSE, keep = FALSE, name = NULL, ...)
A pair of data frames, data frame extensions (e.g. a tibble), or lazy data frames (e.g. from dbplyr or dtplyr). See Methods, below, for more details.
A character vector of variables to join by.
If NULL
, the default, *_join()
will perform a natural join, using all
variables in common across x
and y
. A message lists the variables so that you
can check they're correct; suppress the message by supplying by
explicitly.
To join by different variables on x
and y
, use a named vector.
For example, by = c("a" = "b")
will match x$a
to y$b
.
To join by multiple variables, use a vector with length > 1.
For example, by = c("a", "b")
will match x$a
to y$a
and x$b
to
y$b
. Use a named vector to match different variables in x
and y
.
For example, by = c("a" = "b", "c" = "d")
will match x$a
to y$b
and
x$c
to y$d
.
To perform a cross-join, generating all combinations of x
and y
,
use by = character()
.
If x
and y
are not from the same data source,
and copy
is TRUE
, then y
will be copied into the
same src as x
. This allows you to join tables across srcs, but
it is a potentially expensive operation so you must opt into it.
Should the join keys from both x
and y
be preserved in the
output?
The name of the list column nesting joins create.
If NULL
the name of y
is used.
Other parameters passed onto methods.
This function is a generic, which means that packages can provide implementations (methods) for other classes. See the documentation of individual methods for extra arguments and differences in behaviour.
The following methods are currently available in loaded packages: dplyr:::methods_rd("nest_join").
In some sense, a nest_join()
is the most fundamental join since you can
recreate the other joins from it:
inner_join()
is a nest_join()
plus tidyr::unnest()
left_join()
nest_join()
plus unnest(.drop = FALSE)
.
semi_join()
is a nest_join()
plus a filter()
where you check
that every element of data has at least one row,
anti_join()
is a nest_join()
plus a filter()
where you check every
element has zero rows.
Other joins:
filter-joins
,
mutate-joins
band_members %>% nest_join(band_instruments)
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