Create Unique Index

SQLite

To prevent duplicate entries, create a unique index named ident_ix on the ident column of the staff table.

Expected result Columns: 4 · Rows: 1

table_name	index_name	column_name	is_unique

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.

department - table of departments.

ident	name	building
gen	Genetics	Chesson

little_penguins - table of little penguins.

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.

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.

ident	personal	family	dept	age
7	Abram	Chokshi	gen	23

machine - table of machines.