Я пытаюсь удалить дубликаты строк из моей таблицы mysql. Я пробовал несколько запросов, но продолжаю получать эту ошибку: #1093 - You can't specify target table 'usa_city' for update in FROM clause
Таблица выглядит так:
usa_city
--------
id(pk)
id_state
city_name
И запросы, которые я устал были:
DELETE FROM usa_city
WHERE id NOT IN
(
SELECT MIN(id)
FROM usa_city
GROUP BY city_name, id_state
)
И:
DELETE
FROM usa_city
WHERE usa_city.id IN
-- List 1 - all rows that have duplicates
(SELECT F.id
FROM usa_city AS F
WHERE Exists (SELECT city_name, id_state, Count(id)
FROM usa_city
WHERE usa_city.city_name = F.city_name
AND usa_city.id_state = F.id_state
GROUP BY usa_city.city_name, usa_city.id_state
HAVING Count(usa_city.id) > 1))
AND usa_city.id NOT IN
-- List 2 - one row from each set of duplicate
(SELECT Min(id)
FROM usa_city AS F
WHERE Exists (SELECT city_name, id_state, Count(id)
FROM usa_city
WHERE usa_city.city_name = F.city_name
AND usa_city.id_state = F.id_state
GROUP BY usa_city.city_name, usa_city.id_state
HAVING Count(usa_city.id) > 1)
GROUP BY city_name, id_state);
Спасибо заранее.