Du har brug for et delvist indeks. Slip en unik begrænsning i kolonnen name
og opret et delvist indeks på kolonnen:
CREATE TABLE customers (
customer_id serial PRIMARY KEY,
name VARCHAR,
email VARCHAR NOT NULL,
active bool NOT NULL DEFAULT TRUE
);
CREATE UNIQUE INDEX ON customers (name) WHERE active;
INSERT INTO customers (NAME, email) VALUES
('IBM', '[email protected]'),
('Microsoft', '[email protected]'),
('Intel','[email protected]');
Forespørgslen skal se sådan ud:
INSERT INTO customers (name, email)
VALUES
('Microsoft', '[email protected]')
ON CONFLICT (name) WHERE active
DO UPDATE SET email = excluded.email;
SELECT *
FROM customers;
customer_id | name | email | active
-------------+-----------+-----------------------+--------
1 | IBM | [email protected] | t
3 | Intel | [email protected] | t
2 | Microsoft | [email protected] | t
(3 rows)
Bemærk den korrekte brug af den særlige post excluded.
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