Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.8k views
in Technique[技术] by (71.8m points)

r - Can dplyr join on multiple columns or composite key?

I realize that dplyr v3.0 allows you to join on different variables:

left_join(x, y, by = c("a" = "b") will match x.a to y.b

However, is it possible to join on a combination of variables or do I have to add a composite key beforehand?

Something like this:

left_join(x, y, by = c("a c" = "b d") to match the concatenation of [x.a and x.c] to [y.b and y.d]

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Updating to use tibble()

You can pass a named vector of length greater than 1 to the by argument of left_join():

library(dplyr)

d1 <- tibble(
  x = letters[1:3],
  y = LETTERS[1:3],
  a = rnorm(3)
  )

d2 <- tibble(
  x2 = letters[3:1],
  y2 = LETTERS[3:1],
  b = rnorm(3)
  )

left_join(d1, d2, by = c("x" = "x2", "y" = "y2"))

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...