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R/dedup.R

@@ -171,7 +171,23 @@ dedup_faers_ascii <- function(data, deleted_cases = NULL) {
  order = c(-1L, -1L, -1L, -1L, 1L, -1L)
  )
  out <- unique(out, by = "caseid")
-
+ # test code
+ # Following codes are based on
+ # https://stackoverflow.com/questions/69366291/copy-only-one-variable-from-one-r-data-table-to-another-after-matching-on-a-vari 
+ # which should be memory efficient
+ # a <- data.table::data.table(
+ # id = rep(letters[1:2], 5),
+ # var1 = rnorm(10)
+ # )
+ # b <- data.table::data.table(
+ # id = letters,
+ # var2 = rnorm(length(letters))
+ # )
+ # b[a[, paste0(var1, collapse = "/"), by = "id"],
+ # var1 := V1,
+ # on = "id"
+ # ]
+ # b
  # collapse all used drugs, indi, ther states, use it as a whole to identify
  # same cases.
  # match drug, indi, and ther data.