Suppose you come across a table containing 3 fields:
- country name (country_name)
- state name (state_name)
- total population (total_population) # total population for a given state
Using this information, write a function in SQL that returns the following:
state_name | total_population | percent_of_country_population
Note the last field, percent_of_country_population, can be calculated by dividing each individual state's population by the total population of its associated country in the table.