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Data Manipulation Language (DML)

INSERT

With INSERT you can add data into a table

sql
INSERT INTO people (name, age, city)
VALUES ('Adam', 42, 'Rovaniemi'), ('Amanda', 35, 'Rovaniemi');

UPDATE

UPDATE updates the matcing rows

sql
UPDATE people SET city = 'Oulu' WHERE name = 'Adam' AND age = 42;

WARNING

Without WHERE the UPDATE matches every row in table and will update every row

DELETE

Deletes matching row from a table

sql
DELETE FROM people WHERE city = 'Oulu';

WARNING

Without SELECT the DELETE matches every row in table and will delete everything

Safe updates

MySQL Workbench rejects the updates and deletes without any restrictions. If you want to turn it off, it can be done from Edit -> Preferences -> SQL Editor and in the bottom of the screen (scroll down) uncheck Safe Updates

Safe updates

Lapland University of Applied Sciences

© 2026 Juha Petäjäjärvi

© 2026 Juha Petäjäjärvi