有没有办法同时将两个数据集左连接到第三个数据集？

Question

我有一个看起来像这样的数据集 (df1)

ID     |New York Athletes
Base001 Aaron Judge 
Bask001 Kevin Durant
Bask002 Julius Randle
Base002 Max Scherzer

我想在不添加额外列的情况下同时合并其他两个数据集

ID     |TEAM
Bask001 Nets
Bask002 Knicks

ID     |TEAM
Base001 Yankees
Base002 Mets

df1<- df1 %>%
mutate(merge(df1,Base,by="ID",all.x = TRUE))%>%
mutate(merge(.,Base,by="ID",all.x = TRUE))

但是当我这样做时我得到

ID     |New York Athletes|Teams   |Teams.x|Team.y
Base001 Aaron Judge       Yankees  Yankees 
Bask001 Kevin Durant                       Nets
Bask002 Julius Randle                      Knicks
Base002 Max Scherzer      Mets     Mets

我想要这样的东西

ID     |New York Athletes|Teams   
Base001 Aaron Judge       Yankees  
Bask001 Kevin Durant      Nets
Bask002 Julius Randle     Knicks
Base002 Max Scherzer      Mets

Answer 1

编辑后的答案：你实际上需要为此做两个单独的连接。如果您想一次加入多个数据帧，请先尝试，以供将来参考。

library(tidyverse)

df1 <- tribble(~ID, ~`New York Athletes`,
               "Base001", "Aaron Judge",
               "Bask001", "Kevin Durant",
               "Bask002", "Julius Randle",
               "Base002", "Max Scherzer")
df2 <- tribble(~ID,~TEAM,
               "Bask001", "Nets",
               "Bask002", "Knicks")
df3 <- tribble(~ID, ~TEAM,
               "Base001", "Yankees",
               "Base002", "Mets")


df1_1 <- full_join(df2, df3, by = c("ID", "TEAM"))
final_df <- left_join(df1, df1_1, by = "ID"); final_df
#> # A tibble: 4 × 3
#>   ID      `New York Athletes` TEAM   
#>   <chr>   <chr>               <chr>  
#> 1 Base001 Aaron Judge         Yankees
#> 2 Bask001 Kevin Durant        Nets   
#> 3 Bask002 Julius Randle       Knicks 
#> 4 Base002 Max Scherzer        Mets

^{由 reprex package (v2.0.1)}

于 2022-04-15 创建

是的，您可以使用 purrr 函数一次进行多个连接：

library(tidyverse)

df1 <- tibble(x = c("A1", "A2", "B1", "B2"), y = c(1, 2, 3, 4))
df2 <- tibble(x = c("A1", "A2", "B1", "B2"), z = c(4, 5, 6, 7))
df3 <- tibble(x = c("A1", "A2", "B1", "B2"), delta = c(8, 9, 10, 11))

list_of_dataframes <- list(df1, df2, df3)

purrr::reduce(list_of_dataframes, left_join, by = "x")
#> # A tibble: 4 × 4
#>   x         y     z delta
#>   <chr> <dbl> <dbl> <dbl>
#> 1 A1        1     4     8
#> 2 A2        2     5     9
#> 3 B1        3     6    10
#> 4 B2        4     7    11

^{由 reprex package (v2.0.1)}

于 2022-04-15 创建

Answer 2

在基地 R

merge(df1, rbind(df2, df3))

       ID New.York.Athletes    TEAM
1 Base001       Aaron Judge Yankees
2 Base002      Max Scherzer    Mets
3 Bask001      Kevin Durant    Nets
4 Bask002     Julius Randle  Knicks

Answer 3

我认为@KU99 的答案可能是最简单的，但这是另一个使用 coalesce.

的选项

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
df1 <- tibble::tribble(
  ~ID, ~`New York Athletes`, 
"Base001", "Aaron Judge", 
"Bask001", "Kevin Durant",
"Bask002", "Julius Randle",
"Base002", "Max Scherzer")

df2 <- tibble::tibble(ID = c("Bask001", "Bask002"), 
                      TEAM = c("Nets", "Knicks"))

df3 <- tibble::tibble(ID = c("Base001", "Base002"), 
                      TEAM = c("Yankees", "Mets"))

df1 <- df1 %>%
  mutate(merge(.,df2,by="ID",all.x = TRUE))%>%
  mutate(merge(.,df3,by="ID",all.x = TRUE)) %>% 
  select(-TEAM) %>% 
  mutate(TEAM  = coalesce(TEAM.x,TEAM.y )) %>% 
  select(-c(TEAM.x, TEAM.y))

df1
#> # A tibble: 4 × 3
#>   ID      `New York Athletes` TEAM   
#>   <chr>   <chr>               <chr>  
#> 1 Base001 Aaron Judge         Yankees
#> 2 Base002 Max Scherzer        Mets   
#> 3 Bask001 Kevin Durant        Nets   
#> 4 Bask002 Julius Randle       Knicks

^{由 reprex package (v2.0.1)}

于 2022-04-15 创建

Answer 4

您可以使用{powerjoin}

library(powerjoin)
power_left_join(df1, list(df2, df3), by = "ID", conflict = coalesce_xy)
#> # A tibble: 4 × 3
#>   ID      `New York Athletes` TEAM   
#>   <chr>   <chr>               <chr>  
#> 1 Base001 Aaron Judge         Yankees
#> 2 Bask001 Kevin Durant        Nets   
#> 3 Bask002 Julius Randle       Knicks 
#> 4 Base002 Max Scherzer        Mets

^{由 reprex package (v2.0.1)}

创建于 2022-04-16

有没有办法同时将两个数据集左连接到第三个数据集？

Is there a way to left join two datasets into a third one at the same time?

r

join