Inner, Left, Right, Outer, Semi and Anti Join for Data Tables
These helper functions perform join operations on data tables. Most of them are basically one-liners. See https://rpubs.com/ronasta/join_data_tables for a overview of join operations in data table or alternatively dplyr's vignette on two table verbs.
ijoin(x, y, by = NULL) ljoin(x, y, by = NULL) rjoin(x, y, by = NULL) ojoin(x, y, by = NULL) sjoin(x, y, by = NULL) ajoin(x, y, by = NULL) ujoin(x, y, all.y = FALSE, by = NULL)
x |
[ |
y |
[ |
by |
[
You may pass a named character vector to merge on columns with different names in |
all.y |
[logical(1)] |
[data.table] with key identical to by.
# Create two tables for demonstration tmp = makeRegistry(file.dir = NA, make.default = FALSE) batchMap(identity, x = 1:6, reg = tmp) x = getJobPars(reg = tmp) y = findJobs(x >= 2 & x <= 5, reg = tmp) y$extra.col = head(letters, nrow(y)) # Inner join: similar to intersect(): keep all columns of x and y with common matches ijoin(x, y) # Left join: use all ids from x, keep all columns of x and y ljoin(x, y) # Right join: use all ids from y, keep all columns of x and y rjoin(x, y) # Outer join: similar to union(): keep all columns of x and y with matches in x or y ojoin(x, y) # Semi join: filter x with matches in y sjoin(x, y) # Anti join: filter x with matches not in y ajoin(x, y) # Updating join: Replace values in x with values in y ujoin(x, y)
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