Finds the first column that can be used as the primary key.

This function loops through the given data.frame and returns the name of the first column it finds that could be used as a primary key. That is, the first column where the length of unique values equals the number of rows.

Usage

find_primary_key_column(df)

Arguments

df

a data.frame to search for a primary key.

Value

the name of the first column that could be a primary key or NULL if one could not be found.