Reports the columns the merge added and how the rows of the two inputs were
matched, in the style of tidylog's join messages. The counts of unmatched
rows are only computed when options(dtlog.detail = "full") (the default);
they cost two additional matching passes over the inputs.
Usage
# S3 method for class 'data.table'
merge(x, y, ...)Arguments
- x, y
The data tables to merge.
- ...
All other arguments of
data.table::merge.data.table().
Value
The merged data table, exactly as data.table::merge.data.table()
returns it.
Examples
a <- data.table::data.table(id = 1:3, v = 1:3)
b <- data.table::data.table(id = 2:4, w = 4:6)
merge(a, b, by = "id")
#> inner_join: added one column (w)
#> > rows only in a (1)
#> > rows only in b (1)
#> > matched rows 2
#> > ===
#> > rows total 2
#> Key: <id>
#> id v w
#> <int> <int> <int>
#> 1: 2 2 4
#> 2: 3 3 5