rename_columns: Make a rename columns node (copies columns not renamed).

In rquery: Relational Query Generator for Data Manipulation at Scale

Make a rename columns node (copies columns not renamed).

Description

Make a rename columns node (copies columns not renamed).

Usage

rename_columns(source, cmap, env = parent.frame())

Arguments

source	source to rename from.
cmap	map written as new column names as keys and old column names as values.
env	environment to look to.

Value

rename columns node.

Examples

if (requireNamespace("DBI", quietly = TRUE) && requireNamespace("RSQLite", quietly = TRUE)) {
  my_db <- DBI::dbConnect(RSQLite::SQLite(), ":memory:")
  d <- rq_copy_to(my_db, 'd',
                   data.frame(AUC = 0.6, R2 = 0.2, z = 3))
  op_tree <- rename_columns(d, c('R2' %:=% 'AUC', 'AUC' %:=% 'R2'))
  cat(format(op_tree))
  sql <- to_sql(op_tree, my_db)
  cat(sql)
  print(DBI::dbGetQuery(my_db, sql))
  DBI::dbDisconnect(my_db)
}

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