column_names: Return column names

In rquery: Relational Query Generator for Data Manipulation at Scale

Return column names

Description

Return column names

Usage

column_names(x, ...)

Arguments

x	rquery operation tree.
...	generic additional arguments

Value

vector of 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(column_names(optree))
  DBI::dbDisconnect(my_db)
}

rquery documentation built on Aug. 20, 2023, 9:06 a.m.