SQL

A special-purpose language designed for managing data held in a relational database.

Basic Select

Name	Preview	Code	Difficulty
Revising the Select Query I	Query the data for all American cities with populations larger than 100,000.	SQL	Easy
Revising the Select Query II	Query the city names for all American cities with populations larger than 120,000.	SQL	Easy
Select All	Query all columns for every row in a table.	SQL	Easy
Select By ID	Query the details of the city with ID 1661.	SQL	Easy
Japanese Cities’ Attributes	Query the attributes of all the cities in Japan.	SQL	Easy
Japanese Cities’ Names	In this challenge, you will query a list of all the Japanese cities’ names.	SQL	Easy
Weather Observation Station 1	Write a query to print the CITY and STATE for each attribute in the STATION table.	SQL	Easy
Weather Observation Station 3	Query a list of unique CITY names with even ID numbers.	SQL	Easy
Weather Observation Station 4	Find the number of duplicate CITY names in STATION.	SQL	Easy
Weather Observation Station 5	Write a query to print the shortest and longest length city name along with the length of the city names.	SQL	Easy
Weather Observation Station 6	Query a list of CITY names beginning with vowels (a, e, i, o, u).	SQL	Easy
Weather Observation Station 7	Query the list of CITY names ending with vowels (a, e, i, o, u) from STATION.	SQL	Easy
Weather Observation Station 8	Query CITY names that start AND end with vowels.	SQL	Easy
Weather Observation Station 9	Query an alphabetically ordered list of CITY names not starting with vowels.	SQL	Easy
Weather Observation Station 10	Query a list of CITY names not ending in vowels.	SQL	Easy
Weather Observation Station 11	Query a list of CITY names not starting or ending with vowels.	SQL	Easy
Weather Observation Station 12	Query an alphabetically ordered list of CITY names not starting and ending with vowels.	SQL	Easy
Higher Than 75 Marks	Query the names of students scoring higher than 75 Marks. Sort the output by the LAST three characters of each name.	SQL	Easy
Employee Names	Print employee names.	SQL	Easy
Employee Salaries	Print the names of employees who earn more than $2000 per month and have worked at the company for less than 10 months.	SQL	Easy

Advanced Select

Name	Preview	Code	Difficulty
Type of Triangle	Query a triangle’s type based on its side lengths.	SQL	Easy
The PADS	Query the name and abbreviated occupation for each person in OCCUPATIONS.	SQL	Medium
Occupations	Pivot the Occupation column so the Name of each person in OCCUPATIONS is displayed underneath their respective Occupation.	SQL	Medium