为什么即使在使用异步等待多个调用后仍然得到空响应？

这是简单的节点路由，其中​​调用异步api.

需要做的是return data循环之后。但它返回空白对象。

try {
  const array = ["brunch", "lunch", "crunch"]
  const data = {}
  array.map(async(d) => {
    const venue = await Venue.find({ "category": { "$in": [d] }})
    data[d] = venue
  })
  return data
} catch(err) {
  throw err
}

请帮助我实现这一目标

有一种更好的方法可以使用 MongoDB 获得所需的结果，并且无需循环，使用聚合框架，您可以在其中运行以下管道，该管道使用$facet https://docs.mongodb.com/manual/reference/operator/aggregation/facet/ as

try {
    const array = ["brunch", "lunch", "crunch"]
    const facet = array.reduce((acc, cur) => {
        acc[cur] = [{ "$match": { "category": cur } }]
        return acc
    }, {})
    const pipeline = [
        { "$match": { "category": { "$in": array } } },
        { "$facet": facet }
    ]
    const results = await Venue.aggregate(pipeline).exec()
    const data = results[0]

    return data
} catch(err) {
    throw err
}

您还可以按类别键对文档进行分组$push https://docs.mongodb.com/manual/reference/operator/aggregation/push/每组的文档，然后转换为文档中的键$replaceRoot https://docs.mongodb.com/manual/reference/operator/aggregation/replaceRoot/ with $arrayToObject https://docs.mongodb.com/manual/reference/operator/aggregation/arrayToObject/

try {
    const array = ["brunch", "lunch", "crunch"]
    const pipeline = [
        { "$match": { "category": { "$in": array } } },
        { "$group": { 
            "_id": "$category",
            "data": { "$push": "$$ROOT" }
        } },
        { "$group": {
            "_id": null,
            "venues": {
                "$push": {
                    "k": "$_id",
                    "v": "$data"
                }
            } 
        } },
        { "$replaceRoot": {
            "newRoot": { "$arrayToObject": "$venues" }
        } }
    ]
    const results = await Venue.aggregate(pipeline).exec()
    const data = results[0]

    return data
} catch(err) {
    throw err
}