DB Quacks SQL Tutorial · Chapter 2
Fifty Shades of Duck
A mysterious penguin in sunglasses waddles up. Agent Duck, secret mission! The Environmental Protection Agency needs different duck species counts, but our data has duplicates - Mallards listed 50 times! Show each species only once.
Your task
Show all the different duck species from the ducks table, with no duplicates. You will be removing duplicate values from your results.
Hint
Look for a keyword that can eliminate duplicate rows from your result set.
Expected result
A list of unique duck species.
Tables
duck_diaries (10 rows)
| column | type |
|---|---|
diary_id | BIGINT |
duck_id | BIGINT |
entry_date | DATE |
diary_text | VARCHAR |
mood | VARCHAR |
duck_surveys (5000 rows)
| column | type |
|---|---|
survey_id | BIGINT |
duck_id | BIGINT |
age | BIGINT |
favorite_food | VARCHAR |
favorite_pond | BIGINT |
swimming_rating | BIGINT |
migration_preference | VARCHAR |
social_behavior | VARCHAR |
health_status | VARCHAR |
activity_level | VARCHAR |
survey_date | DATE |
survey_location | BIGINT |
ducks (15 rows)
| column | type |
|---|---|
id | BIGINT |
name | VARCHAR |
age | BIGINT |
species | VARCHAR |
birth_date | DATE |
arrival_date | DATE |
ponds (3 rows)
| column | type |
|---|---|
pond_id | BIGINT |
pond_name | VARCHAR |
location_lat | DOUBLE |
location_lng | DOUBLE |
capacity | BIGINT |
features | VARCHAR[] |
amenities | VARCHAR[] |
Database: https://dbquacks.com/data/databases/tutorial.duckdb
This page as markdown: https://dbquacks.com/tutorial/8.md