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CREATE TABLE TABLE_A (
`id` INTEGER,
`A_1` INTEGER,
`A_2` INTEGER,
`A_3` INTEGER
);
INSERT INTO TABLE_A
(`id`, `A_1`, `A_2`, `A_3`)
VALUES
('1', '4', '5', '20'),
('2', '1', '4', '50'),
('3', '2', '5', '70');
CREATE TABLE TABLE_B (
`id` INTEGER,
`value` INTEGER
);
INSERT INTO TABLE_B
(`id`, `value`)
VALUES
('1', '1'),
('2', '2'),
('3', '3');
SELECT b.*, ELT(b.value, a.A_1, a.A_2, a.A_3) testA
FROM TABLE_B b INNER JOIN TABLE_A a
ON b.id = a.id;
| id | value | testA |
|---|---|---|
| 1 | 1 | 4 |
| 2 | 2 | 4 |
| 3 | 3 | 70 |