캐글 ​intro_to_sql/02-select-from-where

zero_pollution_query = """SELECT *
                            FROM `bigquery-public-data.openaq.global_air_quality`
                            WHERE value = 0"""​

first_query = """SELECT DISTINCT country
                   FROM `bigquery-public-data.openaq.global_air_quality`
                   WHERE unit = "ppm" """