尝试为我想要的聚合解析 2-d JSON 数组

Question

基本上我想解析这个 JSON 2 天数组（下面的快照数据示例）以总结每个日期的所有病例和死亡值，包括各州。它将忽略州列，只将每个日期的所有州的病例和死亡人数相加。我可以在 SQL 中完成，在 javascript 中很难。

所以最后它看起来像：

JSON 二维数组，如下所示：

{date: "2020-02-17", totalCases: "7", totalDeaths: "1"}
{date: "2020-02-18", totalCases: "150", totalDeaths: "2"}
{date: "2020-02-19",  totalCases: "210", totalDeaths: "3"}
{date: "2020-02-20",  totalCases: "350", totalDeaths: "7"}

要聚合的原始 JSON 对象在下方

138: {date: "2020-02-18", state: "California", fips: "06", cases: "7", deaths: "0"}
139: {date: "2020-02-18", state: "Illinois", fips: "17", cases: "2", deaths: "0"}
140: {date: "2020-02-18", state: "Massachusetts", fips: "25", cases: "1", deaths: "0"}
141: {date: "2020-02-18", state: "Nebraska", fips: "31", cases: "10", deaths: "0"}
142: {date: "2020-02-18", state: "Texas", fips: "48", cases: "2", deaths: "0"}
143: {date: "2020-02-18", state: "Washington", fips: "53", cases: "1", deaths: "0"}
144: {date: "2020-02-18", state: "Wisconsin", fips: "55", cases: "1", deaths: "0"}
145: {date: "2020-02-19", state: "Arizona", fips: "04", cases: "1", deaths: "0"}
146: {date: "2020-02-19", state: "California", fips: "06", cases: "7", deaths: "0"}
147: {date: "2020-02-19", state: "Illinois", fips: "17", cases: "2", deaths: "0"}
148: {date: "2020-02-19", state: "Massachusetts", fips: "25", cases: "1", deaths: "0"}
149: {date: "2020-02-19", state: "Nebraska", fips: "31", cases: "10", deaths: "0"}
150: {date: "2020-02-19", state: "Texas", fips: "48", cases: "2", deaths: "0"}
151: {date: "2020-02-19", state: "Washington", fips: "53", cases: "1", deaths: "0"}
152: {date: "2020-02-19", state: "Wisconsin", fips: "55", cases: "1", deaths: "0"}
153: {date: "2020-02-20", state: "Arizona", fips: "04", cases: "1", deaths: "0"}
154: {date: "2020-02-20", state: "California", fips: "06", cases: "8", deaths: "0"}
155: {date: "2020-02-20", state: "Illinois", fips: "17", cases: "2", deaths: "0"}
156: {date: "2020-02-20", state: "Massachusetts", fips: "25", cases: "1", deaths: "0"}
157: {date: "2020-02-20", state: "Nebraska", fips: "31", cases: "11", deaths: "0"}

Answer 1

您可以使用 reduce。

const records = {
 138: {date: "2020-02-18", state: "California", fips: "06", cases: "7", deaths: "2"},
 139: {date: "2020-02-18", state: "Illinois", fips: "17", cases: "2", deaths: "0"},
 140: {date: "2020-02-18", state: "Massachusetts", fips: "25", cases: "1", deaths: "0"},
 141: {date: "2020-02-18", state: "Nebraska", fips: "31", cases: "10", deaths: "0"},
 142: {date: "2020-02-18", state: "Texas", fips: "48", cases: "2", deaths: "0"},
 143: {date: "2020-02-18", state: "Washington", fips: "53", cases: "1", deaths: "2"},
 144: {date: "2020-02-18", state: "Wisconsin", fips: "55", cases: "1", deaths: "0"},
 145: {date: "2020-02-19", state: "Arizona", fips: "04", cases: "1", deaths: "0"},
 146: {date: "2020-02-19", state: "California", fips: "06", cases: "7", deaths: "0"},
 147: {date: "2020-02-19", state: "Illinois", fips: "17", cases: "2", deaths: "0"},
 148: {date: "2020-02-19", state: "Massachusetts", fips: "25", cases: "1", deaths: "0"},
 149: {date: "2020-02-19", state: "Nebraska", fips: "31", cases: "10", deaths: "0"},
 150: {date: "2020-02-19", state: "Texas", fips: "48", cases: "2", deaths: "0"},
 151: {date: "2020-02-19", state: "Washington", fips: "53", cases: "1", deaths: "0"},
 152: {date: "2020-02-19", state: "Wisconsin", fips: "55", cases: "1", deaths: "0"},
 153: {date: "2020-02-20", state: "Arizona", fips: "04", cases: "1", deaths: "0"},
 154: {date: "2020-02-20", state: "California", fips: "06", cases: "8", deaths: "0"},
 155: {date: "2020-02-20", state: "Illinois", fips: "17", cases: "2", deaths: "0"},
 156: {date: "2020-02-20", state: "Massachusetts", fips: "25", cases: "1", deaths: "0"},
 157: {date: "2020-02-20", state: "Nebraska", fips: "31", cases: "11", deaths: "0"}
};


const res = Object.values(records).reduce((acc, {date, cases, deaths}) => {
 if (acc[date] !== undefined) {
  acc[date].totalCases += (+cases);
  acc[date].totalDeaths += (+deaths);
 } else {
  acc[date] = {date, totalCases: (+cases), totalDeaths: (+deaths)};
 }

 return acc;
}, {});

console.log(res);

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尝试为我想要的聚合解析 2-d JSON 数组

Trying to parse 2-d JSON array for the aggregations I want

javascript

parsing

json

aggregation

multidimensional-array