sql PostgreSQL“Upsert”语句的一个示例：意思是，如果UPDATE失败，则INSERT数据。

Posted 2021-05-13

-- Postgres "UPSERT" statement.
WITH upd AS (
    UPDATE my_table 
    SET os='iOS', os_version='10.3' 
    WHERE account='default' 
    RETURNING *
)
INSERT INTO my_table (
    account, os, os_version
)
SELECT 'default', 'iOS', '10.3'
WHERE NOT EXISTS (
    SELECT * FROM upd
);