mysql实现避免重复插入的sql语句简单写法
INSERT into bridgepeoplecount(floor,endTime,locationDate,count,expoId) SELECT 0,'2016-10-13 01:00:00','2016-10-13',2,'dbffc9cc7dd64c6286bc6da7b57e3415' FROM DUAL WHERE NOT EXISTS (SELECT id FROM bridgepeoplecount WHERE expoId = 'dbffc9cc7dd64c6286bc6da7b57e3415' AND endTime = '2016-10-13 01:00:00' AND floor=0)