rquery (version 0.5.0)

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)

Arguments

source

source to rename from.

cmap

map written as new column names as keys and old column names as values.

Value

rename columns node.

Examples

# NOT RUN {
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)
}

# }