CREATE TABLE test_table (
a INT,
b INT
) ENGINE = InnoDB;
INSERT INTO test_table VALUES (1, 2), (2, 3), (3, 4);
ALTER TABLE test_table ADD COLUMN a_b_sum INT AS (a + b);
SELECT * FROM test_table;
INSERT INTO test_table VALUES (5, 7), (2, 9), (2, 3);
ALTER TABLE test_table ALTER COLUMN a_b_sum SET INVISIBLE;
INSERT INTO test_table VALUES (5, 7), (2, 9), (2, 3);
SELECT a, b, a_b_sum FROM test_table;