我希望有人能帮助我优化并避免以下查询中的文件排序。附上其解释的屏幕截图
SELECT DISTINCT(storages.id),
IF(admin_approve = 1
OR storage_free_auctions.user_id = 167
OR ISNULL(storage_free_auctions.user_id),
auction_date, NULL) AS auction_date1
FROM user_list_storage
JOIN storages ON storages.id = user_list_storage.storage_id
JOIN states ON states.id = storages.state
LEFT JOIN storage_auctions ON storage_auctions.id = (
SELECT storage_auctions.id FROM storage_auctions
LEFT JOIN storage_free_auctions
ON storage_free_auctions.storage_auctions_id=storage_auctions.id
WHERE storage_auctions.storage_id = storages.id
AND storage_auctions.status = 'Active'
AND ( ISNULL(storage_free_auctions.user_id)
OR admin_approve = 1
OR storage_free_auctions.user_id = 167)
AND CONCAT(auction_date,' ',start_time) >= CURDATE()
ORDER BY auction_date ASC LIMIT 1)
LEFT JOIN storage_free_auctions
ON storage_free_auctions.storage_auctions_id=storage_auctions.id
LEFT JOIN storage_auction_units
ON storage_auction_units.storage_auction_id = storage_auctions.id
AND storage_auction_units.status='Active'
WHERE storages.storage_status = 'Active'
AND user_list_storage.user_id = 167
AND user_list_storage.user_list_id = 3
AND (storage_free_auctions.user_id = 167
OR admin_approve = 1
OR ISNULL(storage_free_auctions.user_id)
OR user_list_storage.user_id = 167)
GROUP BY storages.id
order by auction_date1
解释结果的第一行如下。
id:1选择类型:主要表:user_listrongtorage类型:ref可能的密钥:idx_user_list_id、idx_storage_id和idx_user_id键:idx_user_idkey_len:5ref:常量
行:64
额外:使用where;使用临时;使用文件端口
更换
LEFT JOIN storage_auctions
ON storage_auctions.id= (SELECT storage_auctions.id
FROM storage_auctions
LEFT JOIN storage_free_auctions
ON storage_free_auctions.storage_auctions_id = storage_auctions.id
WHERE storage_auctions.storage_id = storages.id
AND storage_auctions.status = 'Active'
AND (ISNULL(storage_free_auctions.user_id)
OR admin_approve = 1
OR storage_free_auctions.user_id = 167)
AND CONCAT(auction_date,' ',start_time) >= CURDATE() ORDER BY auction_date ASC LIMIT 1)
带有
AND EXISTS (SELECT 1
FROM storage_auctions
WHERE storage_auctions.id = storages.id
AND CONCAT(auction_date,' ',start_time) >= CURDATE())
因为你在左联接中的子句是多余的,而且以前也做过,所以你只希望将来存在一个具有相同id的记录,对吧?
其余的联接都可以。它们都基于整数列,如果它们不是主键和runstats,请确保对所有这些id进行索引。