MySQL去除重複記錄（臨時表方法）

查詢重複記錄

SELECT COUNT(*) as repetitions, user_id, period
FROM dk_user_account
GROUP BY user_id, period
HAVING repetitions > 1;

建立臨時表用以記錄去除重複記錄

CREATE TABLE tmp SELECT * FROM dk_user_account GROUP BY user_id,period;

刪除原表

DROP TABLE dk_user_account;

將臨時表改名爲原表

ALTER TABLE tmp RENAME TO dk_user_account;