Return the id column names(s) of a dataset if any. If not, the function returns a NULL object.
col_id(dataset)A data frame object.
Name(s) of identifier column(s). NULL if not.
A dataset is a data table containing variables. A dataset object is a data frame and can be associated with a data dictionary. If no data dictionary is provided with a dataset, a minimum workable data dictionary will be generated as needed within relevant functions. Identifier variable(s) for indexing can be specified by the user. The id values must be non-missing and will be used in functions that require it. If no identifier variable is specified, indexing is handled automatically by the function.
{
col_id(iris)
library(fabR)
iris <- add_index(iris)
iris <- as_dataset(iris, col_id = 'index')
col_id(iris)
}
#> [1] "index"