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

Source: R/drop_columns.R

Note: must keep at least one column.

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)
}

#> mk_td("d", c(
#>   "AUC",
#>   "R2")) %.>%
#>  drop_columns(.,
#>    c('AUC'))
#> SELECT
#>  `R2`
#> FROM (
#>  SELECT
#>   `R2`
#>  FROM
#>   `d`
#> ) tsql_95055157526764533838_0000000000
#>    R2
#> 1 0.2