CREATE?TABLE?`action_log`?(??`pkid`?int(11)?unsigned?NOT?NULL?AUTO_INCREMENT?COMMENT?'主鍵Id',??`enterprise_id`?int(11)?unsigned?NOT?NULL?COMMENT?'企業ACCOUNTID',??`student_id`?int(11)?unsigned?NOT?NULL?COMMENT?'學生ACCOUNTID',??`action_id`?tinyint(1)?NOT?NULL?DEFAULT?'0'?COMMENT?'操作ID',??`content`?varchar(255)?NOT?NULL?DEFAULT?'0'?COMMENT?'操作內容',??`create_time`?datetime?NOT?NULL?COMMENT?'記錄時間',??`scence`?tinyint(1)?DEFAULT?NULL?COMMENT?'行為場景,1:pc,2:wap,3:weixin,4:ios,5:android',??PRIMARY?KEY?(`pkid`),??KEY?`student_id`?(`student_id`)?USING?BTREE??KEY?`enterprise_id`?(`enterprise_id`)?USING?BTREE??KEY?`action_id`?(`action_id`)?USING?BTREE)?ENGINE=InnoDB?AUTO_INCREMENT=22579?DEFAULT?CHARSET=utf8?COMMENT='行為日志表';SQL:?SELECT?COUNT(pkid)?AS?tp_count?FROM?`action_log`?WHERE?(?`create_time`?>=?'2016-08-29?00:00:00'?AND?`create_time`?<=?'2016-08-29?09:33:06'??)?AND?`student_id` >0 ?AND?`action_id`?=?2?LIMIT?1 ?[?RunTime:3.7178s?]60萬數據量，將近4秒在增加create_time索引的情況下student_id>0的條件，索引沒有起作用，查詢時間1.5秒