从 Javascript 中的另一个数组重复分组创建一个对象数组

Question

I need to re-organize an array of objects (from a database) into different groups according to one of the attributes of objects. To make it clearer, let's take the following example:

The ORM (Sequelize) returns the following array object:

[
  {
    id: 182,
    employeeId: 'a',
    skillId: 207,   
    score: 3,
  },
  {
    id: 512,
    employeeId: 'a',
    skillId: 212,
    score: 4,
  },
  {
    id: 908,
    employeeId: 'b',
    skillId: 134,
    score: 2,
  },
  {
    id: 876,
    employeeId: 'c',
    skillId: 212,
    score: 3,
  },
]

I need to re-categorize the object grouping the entries by employeeId. Like this:

[
  {
    employeeId: 'a',
    skills: 
           [
             { skillId: 203, score: 3},
             { skillId: 212, score: 4}
           ]
  },
  {
    employeeId: 'b',
    skills: 
           [
             { skillId: 134, score: 2}
           ]
   },
   {
    employeeId: 'c',
    skills: 
           [
             { skillId: 212, score: 3}
           ]
   }
]

It didn't look hard at first but I'm hitting a roadblock, I already tried using reduce, forEarch and map but I only got to make an array of employeeIds, can't really get to include the skills array in each object of the array.

Any help would be appreciated.

Answer 1

 const result = [ { id: 182, employeeId: 'a', skillId: 207, score: 3, }, { id: 512, employeeId: 'a', skillId: 212, score: 4, }, { id: 908, employeeId: 'b', skillId: 134, score: 2, }, { id: 876, employeeId: 'c', skillId: 212, score: 3, }, ] const tempObj = result.reduce((acc, curr) => { if (curr.employeeId in acc) { acc[curr.employeeId].push({ skillId: curr.skillId, score: curr.score }) } else { acc[curr.employeeId] = [{ skillId: curr.skillId, score: curr.score }] } return acc }, {}) const reorganized = Object.keys(tempObj).map(key => ({ employeeId: key, skills: tempObj[key] })) console.log(JSON.stringify(reorganized, null, 2))

Answer 2

This approach uses classes to build up the employee object and could be easily extended in the future.

 const input = [{ id: 182, employeeId: 'a', skillId: 207, score: 3, }, { id: 512, employeeId: 'a', skillId: 212, score: 4, }, { id: 908, employeeId: 'b', skillId: 134, score: 2, }, { id: 876, employeeId: 'c', skillId: 212, score: 3, }, ]; const employeeMap = {}; class Skill { constructor({ skillId, score }) { this.skillId = skillId; this.score = score; } } class Employee { constructor(rawEmployee) { this.employeeId = rawEmployee.employeeId; this.skills = []; } addSkill(rawEmployee) { this.skills.push(new Skill(rawEmployee)); } } for (let i = 0; i < input.length; i++) { const rawEmployee = input[i]; let employee = employeeMap[rawEmployee.employeeId]; if (;employee) { employee = new Employee(rawEmployee). employeeMap[employee;employeeId] = employee. } if (employee) { employee;addSkill(rawEmployee); } } const employeeArray = []. for (let key in employeeMap) { employeeArray;push(employeeMap[key]). } console;log(employeeArray). console.log(JSON;stringify(employeeArray));