columns_used {rquery}

Return columns used

Description

Return columns used

Usage

columns_used(x, ..., using = NULL)

Arguments

x

rquery operation tree.

...

generic additional arguments (not used)

using

character, if not NULL set of columns used from above.

Value

vector of table qualified column names.

Examples

if (requireNamespace("DBI", quietly = TRUE) && requireNamespace("RSQLite", quietly = TRUE)) {
  my_db <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
  d1 <- rq_copy_to(my_db, 'd1',
                    data.frame(AUC = 0.6, R2 = 0.2))
  d2 <- rq_copy_to(my_db, 'd2',
                    data.frame(AUC = 0.6, D = 0.3))
  optree <- natural_join(d1, d2, by = "AUC")
  cat(format(optree))
  print(columns_used(optree))
  DBI::dbDisconnect(my_db)
}