MySQL 对重复记录的查询

1.查询数据表中重复的数据

mysql> SELECT Sensor_ID FROM SensorAttr where Sensor_ID in (SELECT Sensor_ID FROM Sensorbase group by Sensor_ID HAVING COUNT(Sensor_ID)>1);

2.查询数据表中不重复的数据 ，DISTINCT

SELECT DISTINCT（Sensor_ID) FROM SensorAttr ;