mysql - 查询有什么问题吗？错误语法错误？按无工作分组

Question

我写了一个查询

(SELECT TimeStamp, AVG(FwdHr), W 
 FROM Meter_Data 
 WHERE (TimeStamp Between 1370476500 AND 1370477100 AND DeviceID = '1' 
 GROUP BY MeterID ORDER BY TimeStamp) 
UNION 
(SELECT TimeStamp, AVG(FwdHr), W 
 FROM Meter_Data 
 WHERE TimeStamp Between 1370496006 AND 1370496606 AND DeviceID = '1' 
 GROUP BY MeterID ORDER BY TimeStamp)

我想从表中为两个时间戳之间的每个仪表 ID 选择 avg(FwdHr)

然后将其与具有不同时间间隔的同一查询合并

Answer 1

查询中的括号是不平衡且不必要的。