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我正在尝试在 express js 中设置一个无限制的查询参数。但我无法弄清楚我应该如何在我的代码中实现它。我在用着MongoDB aggeration

我想建立用多个$match阶段搜索的无限方面

像这样工作：

'http://localhost:4000/search?text=mango'
'http://localhost:4000/search?text=mango&key=brand&value=rasna' //unlimited facets.
'http://localhost:4000/search?text=mango&key=brand&value=rasna&key=color&value=yellow'  //unlimited facet parameters

这是我的代码：

app.get("/search", async(request, response) => {
    try {
        const textsearch = request.query.text;

        var keystore = request.query.key;      //storing `key` in 'keystore'
        var valuestore = request.query.value;  //storing `value` in `valuestore`

        if (keystore, valuestore) {

            facetjson = [
             {
                '$match': {
                    [keystore]: `${valuestore}`  //Storing key and value in $match
                }
             }
           ]

            const Pipeline = [{
                    '$search': {
                        'text': {
                            'query': `${textsearch}`,
                            'path': 'title',
                        }
                    }
                },
                {
                    '$limit': 5
                }
            ]

            //Pushing 'facetjson' array into Pipeline array to make a filtered search possible.

            const newitem = insert(Pipeline, Pipeline.length - 1, facetjson) 

            let result = collection.aggregate(newitem).toArray();
            response.send(result);
        } else {
            const Pipeline = [{
                    '$search': {
                        'text': {
                            'query': `${textsearch}`,
                            'path': 'title',
                        }
                    }
                },
                {
                    '$limit': 5
                }
            ]
            let result = collection.aggregate(Pipeline).toArray();
            response.send(result);
        };
    } catch (error) {
        response.status(500).send({ message: error.message });
    }
})

（JSFIDDLE 代码示例）[https://jsfiddle.net/divyanshuking/z0vo589e/]

==>我知道我每次都必须为 single $match, Pair传入数组。做了很多谷歌搜索，我发现我必须使用. 但我不知道如何实现这一点。你们有更好的主意来解决这个问题吗？请帮助我：PipelineKey ValueRest Parameter (...keystore,...valuestore)

4

2 回答 2

1

你为什么不使用 forEach 什么的

function endPoint (req, res) {
const queriesFound ={}

req.query.forEach(query=>{

queriesFound[query]=query;
}

QueriesFound will be an object

{ “Name”:”Name”, “AnotherParam”:”AnotherParam” }

}

//QueriesFound 将是一个对象

{“名称”：“名称”，“另一个参数”：“另一个参数”}

于 2021-07-19T02:21:28.877 回答
0

您的请求 URL 的查询参数结构错误。如果要在 URL 中传递多个 kay/value 对，正确的结构是这样的：

  • 'http://localhost:4000/search?text=mango&brand=rasana&color=yellow

此代码应使用此 URL 结构：

app.get("/search", async(request, response) => {
    try {
        //We need "search pipeline stage" in all conditions. whether we got a key/value pair in query or not. 
        //so we use "search stage" when declare pipeline array;
        let pipeline = [{
            '$search': {
                'text': {
                    'query': `${request.query.text}`,
                    'path': 'title',
                }
            }
        }];
        //If there are keys/values pairs in the query parameters, we add match stage to our pipeline array;
        if(request.query) {
            let match = {}, hasMatchSatge = false;
            for(let item in request.query){
                if(item !=== 'text'){
                   match[item] = request.query[item];
                   hasMatchStage = true;
                }
            }
            if(hasMatchStage) pipeline.push({'$match': match});
        }
        //Finally, we add our "limit stage" to the pipeline array;
        pipeline.push({'$limit' : 5});
        let result = collection.aggregate(pipeline).toArray();
        response.status(200).send(result);
    } catch (error) {
        response.status(500).send({ message: error.message });
    }

})

于 2021-07-20T12:50:43.647 回答