dm_select {dm}

Select columns

Description

Select columns of your dm using syntax that is similar to dplyr::select().

Usage

dm_select(dm, table, ...)

Arguments

dm

A dm object.

table

A table in the dm.

...

One or more unquoted expressions separated by commas. You can treat variable names as if they were positions, and use expressions like x:y to select the ranges of variables.

Use named arguments, e.g. new_name = old_name, to rename the selected variables.

The arguments in ... are automatically quoted and evaluated in a context where column names represent column positions. They also support unquoting and splicing. See vignette("programming", package = "dplyr") for an introduction to those concepts.

See select helpers for more details, and the examples about tidyselect helpers, such as starts_with(), everything(), ...

Details

If key columns are renamed, then the meta-information of the dm is updated accordingly. If key columns are removed, then all related relations are dropped as well.

Value

An updated dm with the columns of table reduced and/or renamed.

Examples

dm_nycflights13() %>%
  dm_select(airports, code = faa, altitude = alt)