Task

Missing Data

SQLite

Identify and retrieve all information about machines that do not have an acquisition date recorded in their details (JSON does not contain acquired field).

Expected result Columns: 3 · Rows: 1

ident	name	details

Write your query below and click "Check it!". Tables are described in the right pane.

Tutorial

The query result will appear here. Ctrl+Enter - Run query

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.

More about the Querynomicon database: schema, sample queries and all exercises →

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"}