You can use the merge function with it's optional parameters
Inner join: merge(data1, data2) will work .
This is because R joins the frames by common variable names.
To make sure that you are matching by only those fields that you desire, you can specify the 'by' parameter like this:
merge(df1, df2, by = "Cust_Id")
You can also use the by.x and by.y parameters if the matching variables have different names and are present in different data frames.
For all other joins you can use the commands mentioned below:
Outer join: merge(x = data1, y = data2, by = "Cust_Id", all = TRUE)
Left outer: merge(x = data1, y = data2, by = "Cust_Id", all.x = TRUE)
Right outer: merge(x = data1, y = data2, by = "Cust_Id", all.y = TRUE)
Cross join: merge(x = data1, y = data2, by = NULL)