通过以下查询,我创建一个表,该表是两个现有表左连接的结果:
CREATE TABLE meal_reservations
SELECT
meal.id,
meal.max_reservations,
SUM(IFNULL(reservation.number_of_guests, 0)) AS reservations
FROM meal
LEFT OUTER JOIN reservation
ON meal.id = reservation.meal_id
GROUP BY meal.id;
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我希望能够SELECT在需要时使用相同的查询更新其值。
我尝试过REPLACE INTO,但这只是将新结果附加到现有行上。