在整个集合的字符串字段中查找最常用的单词 [英] Finding most commonly used word in a string field throughout a collection

问题描述

假设我有一个类似于以下内容的Mongo集合:

Let's say I have a Mongo collection similar to the following:

[
  { "foo": "bar baz boo" },
  { "foo": "bar baz" },
  { "foo": "boo baz" }
]

是否可以确定哪个词在foo字段中出现频率最高(理想情况下是带有计数)?

Is it possible to determine which words appear most often within the foo field (ideally with a count)?

例如，我很喜欢这样的结果集:

For instance, I'd love a result set of something like:

[
  { "baz" : 3 },
  { "boo" : 2 },
  { "bar" : 2 }
]

推荐答案

最近关闭了 JIRA问题有关要在聚合框架的$project阶段中使用的$split运算符.
在此位置上，您可以创建这样的管道

There was recently closed a JIRA issue about a $split operator to be used in the $project stage of the aggregation framework.
With that in place you could create a pipeline like this

db.yourColl.aggregate([
    {
        $project: {
            words: { $split: ["$foo", " "] }
        }
    },
    {
        $unwind: {
            path: "$words"
        }
    },
    {
        $group: {
            _id: "$words",
            count: { $sum: 1 }
        }
    }
])

结果看起来像这样

/* 1 */
{
    "_id" : "baz",
    "count" : 3.0
}

/* 2 */
{
    "_id" : "boo",
    "count" : 2.0
}

/* 3 */
{
    "_id" : "bar",
    "count" : 2.0
}

这篇关于在整个集合的字符串字段中查找最常用的单词的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！