rquery (version 1.4.99)

rename_columns: 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())

Value

rename columns node.

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.

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)
}

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