Actual statistics

To keep the penguins_by_islands table (created in this task) up to date, you need to write a trigger that fires after rows are added to the penguins table.
The trigger code should update the number of penguins in the corresponding record of the resulting table, or create a new record if a penguin is added for an island that is not yet in the table.

Use SQLite syntax to write your answer. Descriptions of tables are provided in the right pane.

Write your request in the field below and click the "Check it!" button.

Get hint

Copy code Clear editor

Querynomicon Database: table structure and overview

Querynomicon (SQLite) is a compact training database for learning SQL fundamentals with clear and simple examples.

This page presents the tables, key columns, and sample rows for hands-on SQL practice.

The Querynomicon database contains 5 main tables.

List of tables

department - table of departments.

identDepartment ID
nameDepartment name
buildingBuilding name

ident	name	building
gen	Genetics	Chesson

little_penguins - table of little penguins.

speciesPenguin species
islandIsland of residence
bill_length_mmBill length, mm
bill_depth_mmBill depth, mm
flipper_length_mmFlipper length, mm
body_mass_gBody mass, g
sexSex

species	island	bill_length_mm	bill_depth_mm	flipper_length_mm	body_mass_g	sex
Gentoo	Biscoe	52.1	17	230	5550	MALE

penguins - table of penguins.

speciesPenguin species
islandIsland of residence
bill_length_mmBill length, mm
bill_depth_mmBill depth, mm
flipper_length_mmFlipper length, mm
body_mass_gBody mass, g
sexSex

species	island	bill_length_mm	bill_depth_mm	flipper_length_mm	body_mass_g	sex
Gentoo	Biscoe	52.1	17	230	5550	MALE

staff - table of employees.

identEmployee number
personalEmployee first name
familyEmployee last name
deptDepartment
ageAge

ident	personal	family	dept	age
7	Abram	Chokshi	gen	23

machine - table of machines.

identMachine ID
nameMachine name
detailsJSON with details

ident	name	details
1	WY401	{"acquired": "2023-05-01"}
2	Inphormex	{"acquired": "2021-07-15", "refurbished": "2023-10-22"}
3	AutoPlate 9000	{"note": "needs software update"}

SQL Essentials for Data Analysis: A 50-Day Hands-on Challenge Book by Benjamin Bennett Alexander

If you’re wondering whether you should learn SQL, the answer is simple: absolutely. SQL (Structured Query Language) is the language of data, and data powers every modern business. Whether you’re a data analyst, data scientist, business analyst, software engineer, financial analyst, product manager, or marketing professional, SQL helps you retrieve, analyze, and understand the information that drives decisions.

Practice

Lessons

Test

Actual statistics

Querynomicon Database: table structure and overview

List of tables

Login

Register

Actual statistics

Querynomicon Database: table structure and overview

List of tables