高级SQL语句编写 统计各个城市的总运费及平均每单的运费teledb=# select sum(amount) over(partition by begincity),avg(amount) over(partition by begincity),begincity,amount from bills; sum | avg | begincity | amount ----------+------------------+-----------+--------- 32316.28 | 6463.256 | 三门峡市