1. 错误:select list expression not prduced by aggregation ouput(missing from GROUP BY caluse?) 1. 原因:查询时查询结果的别名与group by字句中的列名冲突,如: ``` sql select sum(dd) as b from a group by b, c ``` 2. 解决方法:将查询结果中的列别名进行修改即可;