drop_columns: Make a drop columns node (not a relational operation).

In WinVector/rquery: Relational Query Generator for Data Manipulation at Scale

Make a drop columns node (not a relational operation).

Description

Note: must keep at least one column.

Usage

drop_columns(source, drops, ..., strict = FALSE, env = parent.frame())

Arguments

source	source to drop columns from.
drops	list of distinct column names.
...	force later arguments to bind by name
strict	logical, if TRUE do check columns to be dropped are actually present.
env	environment to look to.

Value

drop 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))
  optree <- drop_columns(d, 'AUC')
  cat(format(optree))
  sql <- to_sql(optree, my_db)
  cat(sql)
  print(DBI::dbGetQuery(my_db, sql))
  DBI::dbDisconnect(my_db)
}

WinVector/rquery documentation built on Aug. 24, 2023, 11:12 a.m.