数据归类技术

关联表

• 用户表

id	name	sex
1	小明	1
2	小黄	1
3	小红	2
4	小绿	2

• 性别表

id	sex
1	男
2	女

var users = [
  {id: 1, name: '小明', sex: 1},
  {id: 2, name: '小黄', sex: 1},
  {id: 3, name: '小红', sex: 2},
  {id: 4, name: '小绿', sex: 3}
]
var sex = [
  {id: 1, sex: '男'},
  {id: 2, sex: '女'}
]

单一归类

// {
//   1: [
//     {id: 1, name: '小明', sex: 1},
//     {id: 2, name: '小黄', sex: 1},
//   ],
//   2: [
//     {id: 3, name: '小红', sex: 2},
//     {id: 4, name: '小绿', sex: 3}
//   ]
// }
var cache = {}
sex.forEach(function (sex) {
  var _id = sex.id;
  cache[_id] = []
  users.forEach(function(user) {
    var _sex = user.sex;
    if (_sex == _id) {
      cache[_id].push(user)
    }
  })
})
console.log(cache)

复合归类

id	name
1	足球
2	篮球

name	hobby
小明	1,2
小花	2

var hobby = [
  {id:1, name: '足球'},
  {id:2, name: '篮球'},
  {id:3, name: '排球'},
  {id:4, name: '乒乓球'},
  {id:5, name: '保龄球'},
  {id:6, name: '高尔夫球'},
]
var person = [
  {name: '小明', hobby: '1,2'},
  {name: '小明', hobby: '1,3'},
  {name: '小明', hobby: '2,5'},
  {name: '小明', hobby: '5,6'},
  {name: '小明', hobby: '3,5'},
  {name: '小明', hobby: '1,2,6'},
  {name: '小明', hobby: '3,6'},
  {name: '小明', hobby: '1,4,5,6'},
]

var cache = {
  1: [{name: '小明', hobby: '1,2'},{name: '小明', hobby: '1,2,6'},{name: '小明', hobby: '1,4,5,6'}],
  2: [{name: '小明', hobby: '1,2'},{name: '小明', hobby: '2,5'},{name: '小明', hobby: '1,2,6'}],
  3: [{name: '小明', hobby: '1,3'},{name: '小明', hobby: '3,5'},{name: '小明', hobby: '3,6'}]
  ...
}
hobby.forEach(function(hobby) {
  var _id = hobby.id;
  cache[_id] = [];
  person.forEach(function(person) {
    var _hobbyArr = person.hobby.split(',');
    _hobbyArr.forEach(function(elem) {
      if (elem ++ _id) {
        cache[_id].push(person)
      }
    })
  })
})
console.log(cache)

function sortDatas(sort, data) {
  var cache = {};

  // foreign_key 关联字段
  return function(foreign_key, sortType) {
    if(sortType !== 'single' && sortType !== 'multi') {
      throw new Error('Invalid sort type,[Only "single" and "multi" are valid values')
    }
    sort.forEach(function(sort) {
      var _id = sort.id;
      cache[_id] = []
      data.forEach(function(elem) {
        var foreign_val = elem[foreign_key]
        switch(sortType) {
          case 'single':
            if (foreign_val == _id) {
              cache[_id].push(elem)
            }
            break;
          case 'multi':
            var _arr = foreign_val.split(',')
            _arr.forEach(function(val) {
              if (val === _id) {
                cache[_id].push(elem)
              }
            })
            break;
          default:
            break;
        }
      })
      return cache;
    })
  }
}