check_key: Check if column(s) can be used as keys

In dm: Relational Data Models

Check if column(s) can be used as keys

Description

check_key() accepts a data frame and, optionally, columns. It throws an error if the specified columns are NOT a unique key of the data frame. If the columns given in the ellipsis ARE a key, the data frame itself is returned silently, so that it can be used for piping.

Usage

check_key(x, ..., .data = deprecated())

Arguments

x	The data frame whose columns should be tested for key properties.
...	The names of the columns to be checked, processed with dplyr::select(). If omitted, all columns will be checked.
.data	Deprecated.

Value

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

Examples

data <- tibble::tibble(a = c(1, 2, 1), b = c(1, 4, 1), c = c(5, 6, 7))
# this is failing:
try(check_key(data, a, b))

# this is passing:
check_key(data, a, c)
check_key(data)

dm documentation built on May 29, 2024, 11:41 a.m.