R left_join() replacing joined values rather than adding in new columns - r

Question

I have the following dataframes:
A<-data.frame(AgentNo=c(1,2,3,4,5,6),
N=c(2,5,6,1,9,0),
Rarity=c(1,2,1,1,2,2))
AgentNo N Rarity
1 1 2 1
2 2 5 2
3 3 6 1
4 4 1 1
5 5 9 2
6 6 0 2
B<-data.frame(Rank=c(1,5),
AgentNo.x=c(2,5),
AgentNo.y=c(1,4),
N=c(3,1),
Rarity=c(1,2))
Rank AgentNo.x AgentNo.y N Rarity
1 1 2 1 3 1
2 5 5 4 1 2
I would like to left join B onto A by columns "AgentNo"="AgentNo.y" and "N"="N" but rather than add new columns to A from B I want the same columns from A but where joined values have been updated and taken from B.
For any joined rows I want A.AgentNo to now be B.AgentNo.x, A.N to be B.N and A.Rarity to be B.Rarity. I would like to drop B.Rank and B.Agent.y completely.
The result should be:
Result<-data.frame(AgentNo=c(2,2,3,5,5,6), N=c(2,5,6,1,9,0), Rarity=c(1,2,1,1,2,2))
AgentNo N Rarity
1 2 3 1
2 2 5 2
3 3 6 1
4 5 1 2
5 5 9 2
6 6 0 2

Answer 1

After some data wrangling, you can use rows_update to update the rows of A by the values of B:
library(dplyr)
A <- A %>%
mutate(AgentNo.y = AgentNo)
B <- select(B, AgentNo = AgentNo.x, AgentNo.y, N, Rarity)
rows_update(A, B, by = "AgentNo.y") %>%
select(-AgentNo.y)
output
AgentNo N Rarity
1 2 3 1
2 2 5 2
3 3 6 1
4 5 1 1
5 5 9 2
6 6 0 2