=1 OR confirm IS NULL ;SELECT dtime,id FROM salesdata WHERE IFNULL=1 ;我的数据库在虚拟机中运行,大约有一万条记录:mysql Ver 15.1 Distrib 10.1.41-MariaDB更新:(我根据Akina的指南添加了更多信息)
时长/拉取时间: 0.0034秒</
from logs ordered by log_date desc表中大约有4000万行--> 0.032秒拉取select * from logs where log_id < 500 order by log_time desc;$max是最大log_id,已在另一个查询中检索到它select * from logs where log_id > ($max - 50
我已经找到了= vs用于单个值(链接和链接)的帖子,但实际上我要求的是多个值。它可能表现得更好:SELECT * FROM tbl WHERE id = 50 OR id = 51 OR id = 52
SELECT * FROM tbl WHERE id IN (50, 51, 52)
SELECT * FROM tbl WHERE id >= 50 AND id <= 52
注意:很明显,id是主索引的。