+-------------+---------+
|Column Name |Type|+-------------+---------+
|state| varchar || city | varchar |+-------------+---------+
(state, city) is the primarykey (combination of columns withuniquevalues) for this table.
Eachrowof this tablecontains the state name and the city name within that state.
Write a solution to find all the cities in each state and combine them into a single comma-separated string.
Return the result table ordered bystateandcityinascending order.
Input:
cities table:+-------------+---------------+| state | city |+-------------+---------------+| California | Los Angeles || California | San Francisco || California | San Diego || Texas | Houston || Texas | Austin || Texas | Dallas || New York | New York City || New York | Buffalo || New York | Rochester |+-------------+---------------+Output:
+-------------+---------------------------------------+| state | cities |+-------------+---------------------------------------+| California | Los Angeles, San Diego, San Francisco || New York | Buffalo, New York City, Rochester || Texas | Austin, Dallas, Houston |+-------------+---------------------------------------+Explanation:
***California:** All cities("Los Angeles","San Diego","San Francisco") are listed in a comma-separated string.***New York:** All cities("Buffalo","New York City","Rochester") are listed in a comma-separated string.***Texas:** All cities("Austin","Dallas","Houston") are listed in a comma-separated string.**Note:** The output table is ordered by the state name in ascending order.
To list all cities in each state as a single comma-separated string, we need to group the cities by state and concatenate the city names in sorted order.