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我有以下收集MongoDB的聚集
{ "data" :[
{ "country" :"USA", "state": "NJ", "County" : "Middlesex", "city" : "Edison", "population" :0923422 },
{ "country" :"USA", "state": "NJ", "County" : "Mercer", "city" : "Princeton", "population" :0923422 },
{ "country" :"USA", "state": "NY", "County" : "Middlesex", "city" : "Edison", "population" :234234 },
{ "country" :"USA", "state": "NY", "County" : "Ocean", "city" : "Albony", "population" :234324 },
{ "country" :"USA", "state": "PA", "County" : "Central", "city" : "Edison", "population" :0923422 },
{ "country" :"USA", "state": "NJ", "County" : "Middlesex", "city" : "Edison", "population" :23432 },
{ "country" :"USA", "state": "OH", "County" : "Middlesex", "city" : "Cincinatti", "population" :0923422 },
{ "country" :"USA", "state": "OH", "County" : "Middlesex", "city" : "Columbos", "population" :23432 } ]
}
希望找到由國家,州,縣,市的總人口與MongoDB中嵌套的聚集。
請幫忙查詢。
真的是一個具有挑戰性的。無法以不同的格式製作。 – notionquest