Using one data.frame to update another

Question

Given 2 data frames that are identical in terms of column names/datatypes, where some columns uniquely identify the rows, is there an efficient function/method for one data.

Answer 1

Just set a unique ID as the row names. Then it is simple indexing:

rownames(original) = original$Id
rownames(replacement) = replacement$Id

original[rownames(replacement), ] = replacement