如何根据key id合并Json对象？

Question

I have a json like that. Now I want to merge it on the basis of articleId.

                   [{
                        "articleId": "45",
                        "isA": false,
                        "flags": {
                            "isDema": false,
                            "isCont": true,
                        },
                        "Proc": [
                            {
                                "level1": "tt",
                                "description": "I am well"
                            }
                        ],
                        "isAlert": false
                    },
                    {
                        "articleId": "46",
                        "isA": false,
                        "flags": {
                            "isDema": false,
                            "isCont": true,
                        },
                        "Proc": [
                            {
                                "level1": "ty",
                                "description": "I am fine"
                            }
                        ],
                        "isAlert": false
                    },
                    {
                        "articleId": "45",
                        "isA": false,
                        "flags": {
                            "isDema": false,
                            "isCont": true,
                        },
                        "Proc": [
                            {
                                "level1": "tt",
                                "description": "I am beautiful"
                            }
                        ],
                        "isAlert": false
                    }];

We see here article id 45 is two time although description field is different. SO I want to add description in one array. After merge it I want to get a output like that.

[{
                        "articleId": "45",
                        "isA": false,
                        "flags": {
                            "isDema": false,
                            "isCont": true,
                        },
                        "Proc": [
                            {
                                "level1": "tt",
                                "description":[
                                             "I am well",
                                             "I am beautiful"
                                           ]
                            }
                        ],
                        "isAlert": false
                    },
                    {
                        "articleId": "46",
                        "isA": false,
                        "flags": {
                            "isDema": false,
                            "isCont": true,
                        },
                        "Proc": [
                            {
                                "level1": "ty",
                                "description": "I am fine"
                            }
                        ],
                        "isAlert": false
                    }];

I am trying it direct string parse. Is there any other way ? By the way I am using node js. Is there any built in method that can merge two json object ?

Answer 1

You probably have to write your own merge function - something like this:

var json = [{
    "articleId": "45",
    "isA": false,
    "flags": {
        "isDema": false,
        "isCont": true,
    },
    "Proc": [{
        "level1": "tt",
        "description": "I am well"
    }],
    "isAlert": false
}, {
    "articleId": "46",
    "isA": false,
    "flags": {
        "isDema": false,
        "isCont": true,
    },
    "Proc": [{
        "level1": "ty",
        "description": "I am fine"
    }],
    "isAlert": false
}, {
    "articleId": "45",
    "isA": false,
    "flags": {
        "isDema": false,
        "isCont": true,
    },
    "Proc": [{
        "level1": "tt",
        "description": "I am beautiful"
    }],
    "isAlert": false
}];

const merged = json.reduce((acc,item)=>{
    const found = acc.find(article=>article.articleId === item.articleId)
    if (!found) {
        acc.push(item)
    } else if (found.Proc[0].description !== item.Proc[0].description) {
        found.Proc[0].description = [found.Proc[0].description, item.Proc[0].description]
    }
    return acc;
}
, [])

console.log(merged)

However, this example assumes you never have more than 1 item in Proc , so you have to deal with that. Also if some other keys differ when merging, you have to write logic how to deal with those. What if "isA" is different? would it end up being "isA": [false, true] ?

In the end, it's a bad practice to change datatype, from string to array of strings after merging. This will lead to spaghetti code eventually

Answer 2

So you want to eliminate duplicates based on the child object articleId. Now suppose you have stored your initial array inside variable data.

This might solve your problem.

let articleIdSet = new Set();
let newData = [];
data.map((item) => {
    const { articleId }= item;
    if(articleIdSet.has(articleId)) return; // return if the id is already present
    else {
      articleIdSet.add(articleId); // else add new id into the set
      newData.push(item);          // and push the item into new array
    }
})

Now newData would contain non-duplicate items.

Answer 3

Try for the following:

 var arr = [{ "articleId": "45", "isA": false, "flags": { "isDema": false, "isCont": true, }, "Proc": [{ "level1": "tt", "description": "I am well" }], "isAlert": false }, { "articleId": "46", "isA": false, "flags": { "isDema": false, "isCont": true, }, "Proc": [{ "level1": "ty", "description": "I am fine" }], "isAlert": false }, { "articleId": "45", "isA": false, "flags": { "isDema": false, "isCont": true, }, "Proc": [{ "level1": "tt", "description": "I am beautiful" }], "isAlert": false } ]; var fianlArr = []; arr.map(function(element) { var filterArr = fianlArr.filter(finalArrEle => finalArrEle.articleId === element.articleId); if (filterArr.length) { var proc = []; var desc = []; var obj = {}; obj.level1 = element.Proc[0].level1; desc.push(filterArr[0].Proc[0].description); desc.push(element.Proc[0].description); obj.description = desc; proc.push(obj); fianlArr[fianlArr.indexOf(filterArr[0])].Proc = proc; } else { fianlArr.push(element); } }) console.log("fianlArr", fianlArr)

The JSON structure the above should have always the same structure.

Answer 4

Group by articleId using a map where key is the articleId:

const source = [{"articleId":"45","isA":false,"flags":{"isDema":false,"isCont":true},"Proc":[{"level1":"tt","description":"I am well"}],"isAlert":false},{"articleId":"46","isA":false,"flags":{"isDema":false,"isCont":true},"Proc":[{"level1":"ty","description":"I am fine"}],"isAlert":false},{"articleId":"45","isA":false,"flags":{"isDema":false,"isCont":true},"Proc":[{"level1":"tt","description":"I am beautiful"}],"isAlert":false}];

const bucket = {}
source.map((item) => {
    const merged = bucket[item.articleId];
    if (!merged) {
        item.Proc[0].description = [item.Proc[0].description]
        bucket[item.articleId] = item;
        return;
    }
    merged.Proc[0].description.push(item.Proc[0].description)
});

const out = [];
for (const key in bucket) {
    const val = bucket[key];
    if (val.Proc[0].description.length === 1) {
        val.Proc[0].description = val.Proc[0].description.pop();
    }
    out.push(val);
}

console.log(JSON.stringify(out));

Answer 5

 var before = [{ "articleId": "45", "isA": false, "flags": { "isDema": false, "isCont": true, }, "Proc": [ { "level1": "tt", "description": "I am well" } ], "isAlert": false }, { "articleId": "46", "isA": false, "flags": { "isDema": false, "isCont": true, }, "Proc": [ { "level1": "ty", "description": "I am fine" } ], "isAlert": false }, { "articleId": "45", "isA": false, "flags": { "isDema": false, "isCont": true, }, "Proc": [ { "level1": "tt", "description": "I am beautiful" } ], "isAlert": false }]; var articles = []; let results = []; before.forEach((item) => { if (!articles.includes(item.articleId)) { articles.push(item.articleId); var obj = { "articleId": item.articleId, "isA": item.isA, "flags": { "isDema": item.flags.isDema, "isCont": item.flags.isCont, }, "Proc": [ { "level1": item.Proc.level1, "description": [item.Proc[0].description] } ], "isAlert": false } results.push(obj); } else { var index = articles.indexOf(item.articleId); results[index].Proc[0].description.push(item.Proc[0].description); } }) console.log(JSON.stringify(results));

The above solution is an answer to your solution. But I'd rather if you make the Proc just an object because it doesn't have more than one object in it. If it has more than one objects in different situations let me know I'll improve this answer.