Join more than two tables

[fgaascht]

Hi,

I have four tables I would like to join.
When I want to join two tables, I use dplyr and the command

NewDataFrame <-left_join(Table1, Table2, by="SharedColumn")

I tried with four tables

NewDataFrame <-left_join(Table1, Table2, Table3, Table4, by="SharedColumn")

But of course it does not work.

Is there an easy or more clean approach other than combining table1 and table2, then table 3, then table4?

Thank you in advance.

[DavoWW]

Hi @fgaascht,
Try using purrr like this:

library(tidyverse)
dfs <- list(
  a = data.frame(x = 1:10, a = runif(10)),
  b = data.frame(x = 1:10, b = runif(10)),
  c = data.frame(x = 1:10, c = runif(10)))
purrr::reduce(dfs, left_join) 

HTH

[c_penfold]

An alternative approach would be to pipe (%>%) the steps together, like this:

library(tidyverse)
NewDataFrame <- left_join(Table1, Table2, by="SharedColumn") %>%
                left_join(Table3, by="SharedColumn") %>%
                left_join(Table4, by="SharedColumn")

The pipe operator %>% takes the result of the first left_join and inputs it into the second, and then into the third left_join.