Increment value

CREATE TABLE people (
    name TEXT,
    grade INTEGER
);

INSERT INTO people (name, grade) VALUES ('Joe', 40);
INSERT INTO people (name, grade) VALUES ('Jane', 60);
SELECT * from people;
SELECT '-------';

SELECT 'Incrementing the grade of Joe by 1';
UPDATE people SET grade = (SELECT grade FROM people WHERE name = 'Joe') + 1 WHERE name = 'Joe';
SELECT * from people;
SELECT '-------';

SELECT 'Incrementing the grade of every person by 5';
UPDATE people SET grade = grade + 5;
SELECT * from people;
SELECT '-------';

sqmlite3 < examples/increment.sql

Joe|40
Jane|60
-------
Incrementing the grade of Joe by 1
Joe|41
Jane|60
-------
Incrementing the grade of every person by 5
Joe|46
Jane|65
-------