check_subset: Check column values for subset

In dm: Relational Data Models

Check column values for subset

Description

check_subset() tests if x is a subset of y. For convenience, the x_select and y_select arguments allow restricting the check to a set of key columns without affecting the return value.

Usage

check_subset(x, y, ..., x_select = NULL, y_select = NULL, by_position = NULL)

Arguments

x, y	A data frame or lazy table.
...	These dots are for future extensions and must be empty.
x_select, y_select	Key columns to restrict the check, processed with dplyr::select().
by_position	Set to TRUE to ignore column names and match by position instead. The default means matching by name, use x_select and/or y_select to align the names.

Value

Returns x, invisibly, if the check is passed. Otherwise an error is thrown and the reason for it is explained.

Examples

data_1 <- tibble::tibble(a = c(1, 2, 1), b = c(1, 4, 1), c = c(5, 6, 7))
data_2 <- tibble::tibble(a = c(1, 2, 3), b = c(4, 5, 6), c = c(7, 8, 9))
# this is passing:
check_subset(data_1, data_2, x_select = a, y_select = a)

# this is failing:
try(check_subset(data_2, data_1))

dm documentation built on July 2, 2025, 5:09 p.m.