R根据其他数据帧的匹配将列添加到数据帧？

Question

我有2个看起来像这样的表：

table1 <- data.table("Number" = c(1,2,3,4), Type = c("A", "B", "C", "A"), "Day" = c(3,4,5,2))
table2 <- data.table("Number" = c(1,2,3,4), "Type" = c("A","B","C","A"), "Value" = c(.1, .44, .2, .6))

我想在表1中添加“值”列，它需要根据“数字”和“类型”而不只是“数字”进行匹配！终点表将如下所示：

table1 <- data.table("Number" = c(1,2,3,4), "Type" = c("A","B","C","A"), "Day" = c(3,4,5,2), "Value" = c(.1,.44,.2,.6))

我试图使用match（）函数，但是如果我想同时匹配“数字”和“类型”，我不知道如何使用它。

谢谢！