我在cassandra中具有MAP类型的元素cloumn
elements = [{"a":10,"b":12,"c":13,"d":14},{"a":2,"b":1,"c":5,"d":19},{"a":5,"b":4,"c":13,"d":4},{"a":140,"b":1,"c":4,"d":14}]
我想用Java编写一个聚合函数，该函数可以找到Map Keys的最小最大值，结果将是这样。
[{a "min": 2, "max": 140},{b "min": 1, "max": 5},{c "min": 4, "max": 13},{d "min": 4, "max": 19}]
我从未写过这些东西。需要帮助。