如何使用多个键来选择某些行

Question

例如，我有这样的data.table

library(data.table)

test <- data.table(x=c(rep(c(1:3),3)),y=c("A","B","A","C","C","B","B","B","A"))

enter image description here

我设置了两个键，x和y setkey(test,x,y);

然后我想选择＆＃34; x＆＃34; == 1或2和＆＃34; y＆＃34; ==＆＃34; A＆＃34;或＆＃34; B＆＃34;;

但如果我输入test[list(c(1,2),c("A","B"))] 我错了enter image description here

我怎样才能得到我想要的东西，谢谢!!!