蒙戈德.获取其数组字段仅包含查询中的单词的文档

Question

是否可以在mongodb中找到字段中所有单词都包含在查询中的文档，反之亦然？

伪查询：

{title: 
{$in: ["the", "quick", "brown", "fox", "jumps", "over", "the", "lazy", "dog"]}
}

文档：

{'title': ["brown", "fox"}    #true
{'title': ["lazy", "dog"]}    #true
{'title': ["lazy", "dog", "sleep"]}    #false 'sleep' not in query
{'title': ["brown", "dog"]}    #true
{'title': ["jumps", "quick"]}    #true
{'title': ["smile", "fox"]}    #false 'smile' not in query

Answer 1

MongoDB聚合提供了比标准.find方法更多的操作。

采用两个或多个数组并返回一个包含每个输入数组中显示的元素的数组。 https://docs.mongodb.com/manual/reference/operator/aggregation/setIntersection/#exp._S_setIntersection

一旦我们得到交集，我们比较数组大小(我假设你的数组不能有重复的值(

db.collection.aggregate([
{
$match: {
$expr: {
$eq: [
{
$size: "$title"
},
{
$size: {
$setIntersection: [
"$title",
[
"the",
"quick",
"brown",
"fox",
"jumps",
"over",
"the",
"lazy",
"dog"
]
]
}
}
]
}
}
}
])

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