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

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)
}
#> mk_td("d", c(
#>   "AUC",
#>   "R2",
#>   "z")) %.>%
#>  rename_columns(.,
#>   c('R2' = 'AUC',
#>     'AUC' = 'R2'))
#> SELECT
#>  `AUC` AS `R2`,
#>  `R2` AS `AUC`,
#>  `z` AS `z`
#> FROM (
#>  SELECT
#>   `AUC`,
#>   `R2`,
#>   `z`
#>  FROM
#>   `d`
#> ) tsql_68691819227139042094_0000000000
#>    R2 AUC z
#> 1 0.6 0.2 3