基于多个键对 Json 进行分组

Posted 2023-05-08

【中文标题】基于多个键对 Json 进行分组

【英文标题】：Grouping Json Based on Multiple Keys

【发布时间】：2015-05-06 10:44:54

【问题描述】：

我有一个像下面这样的 Json 结构

[
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I1",
    "item_name": "C1_I1_Name",
    "variant_id": "C1_I1_V1",
    "variant_name": "C1_I1_V1_ Name"
  ,
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I1",
    "item_name": "C1_I1_Name",
    "variant_id": "C1_I1_V2",
    "variant_name": "C1_I1_V2_ Name"
  ,
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I2",
    "item_name": "C1_I2_Name",
    "variant_id": "C1_I2_V1",
    "variant_name": "C1_I2_V1_ Name"
  ,
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I2",
    "item_name": "C1_I2_Name",
    "variant_id": "C1_I2_V2",
    "variant_name": "C1_I2_V2_ Name"
  ,
  
    "category_id": "C2",
    "category_name": "C2_Name",
    "item_id": "C2_I1",
    "item_name": "C2_I1_Name",
    "variant_id": "C2_I1_V1",
    "variant_name": "C2_I1_V1_ Name"
  
]

我想在 javascript 中将 Json 分组为 N' 级别，例如通过传递键列表。例如给出 category_id、item_id 和 variant_id，我期待以下响应：

[
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item": [
      
        "item_id": "C1_I1",
        "item_name": "C1_I1_Name",
        "variant": [
          
            "variant_id": "C1_I1_V1",
            "variant_name": "C1_I1_V1_ Name"
          ,
          
            "variant_id": "C1_I1_V2",
            "variant_name": "C1_I1_V2_ Name"
          
        ]
      ,
      
        "item_id": "C1_I2",
        "item_name": "C1_I2_Name",
        "variant": [
          
            "variant_id": "C1_I2_V1",
            "variant_name": "C1_I2_V1_ Name"
          ,
          
            "variant_id": "C1_I2_V2",
            "variant_name": "C1_I2_V2_ Name"
          
        ]
      
    ]
  
]

需要有关如何解决此问题的帮助吗？

我尝试了类似以下的方法，但它为一个级别分组。我希望它是递归的。

function groupBy(collection, property) 
    var i = 0, val, index, values = [], result = []; 
    for (; i < collection.length; i++)  
        val = collection[i][property]; 
        index = values.indexOf(val); 
        if (index > -1) 
            result[index].push(collection[i]); 
        else  
            values.push(val); result.push([collection[i]]); 
        
     
    return result; 
 

【问题讨论】：

我尝试了类似以下的方法，但它为一个级别分组，我希望它是递归的 [code]function groupBy(collection, property) var i = 0, val, index, values = []，结果 = []； for (; i -1) result[index].push(collection[i]);否则 values.push(val);结果.push([collection[i]]); 返回结果；

您要传递键名或值的列表吗？

键名（在上面的例子中，我需要传递 category_id、item_id、variant_id 作为列表

【参考方案1】：

这是我的任务解决方案（仅限 Javascript）：

function getItemByKey(arr, key, value)
    // here we look for existing group item in the result array
    return arr.reduce(function (prev, cur) 
        if (prev == null && cur[key] == value) 
            return cur;
        
        return prev;
    , null);


function checkPropForGroup(prop, key)
    // here we check which columns should stay in the group,
    // and which should go down to group items.
    return prop == key || prop == key.replace("_id", "_name");


function cloneSuperItem(src, key)
    // create super item by copying only group related fields 
    var item = ;
    for (prop in src)
        if (checkPropForGroup(prop, key))
            item[prop] = src[prop];
        
    
    item[key+'_group'] = [];
    return item;


function cloneSubItem(src, key)
    // create sub-item by copying all but group related fields 
    var item = ;
    for (prop in src)
        if (!checkPropForGroup(prop, key))
            item[prop] = src[prop];
        
    
    return item;


function groupArray(arr, args, lvl)
    var key = args[lvl];
    var result = [];
    arr.forEach(function (item, ind, a)
        // find or create super item for group and then create sub item 
        // and push it there 
        var keyItem = getItemByKey(result, key, item[key]);
        if (!keyItem)
            keyItem = cloneSuperItem(item, key);
            result.push(keyItem);
        
        subItem = cloneSubItem(item, key);
        keyItem[key+'_group'].push(subItem);
    );
    if (args[lvl+1])
        // recursively make grouping on lower level 
        for (var i = 0; i < result.length; i++)
            result[i][key+'_group'] = 
              groupArray(result[i][key+'_group'], args, lvl + 1);
        
    
    return result;


function groupArrayMain(arr, keysArray)
    // keys should be simply listed as parameters in order from top group to lower
    return JSON.stringify(groupArray(arr, arguments, 1),null,'\n')


var arr = [
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I1",
    "item_name": "C1_I1_Name",
    "variant_id": "C1_I1_V1",
    "variant_name": "C1_I1_V1_ Name"
  ,
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I1",
    "item_name": "C1_I1_Name",
    "variant_id": "C1_I1_V2",
    "variant_name": "C1_I1_V2_ Name"
  ,
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I2",
    "item_name": "C1_I2_Name",
    "variant_id": "C1_I2_V1",
    "variant_name": "C1_I2_V1_ Name"
  ,
  
    "category_id": "C1",
    "category_name": "C1_Name",
    "item_id": "C1_I2",
    "item_name": "C1_I2_Name",
    "variant_id": "C1_I2_V2",
    "variant_name": "C1_I2_V2_ Name"
  ,
  
    "category_id": "C2",
    "category_name": "C2_Name",
    "item_id": "C2_I1",
    "item_name": "C2_I1_Name",
    "variant_id": "C2_I1_V1",
    "variant_name": "C2_I1_V1_ Name"
  
]
groupArrayMain(arr, "category_id", "item_id", "variant_id")

我也把它写成jsfiddle