Question

请看这个文件：

{
"creation_date" : ISODate("2015-02-10T03:00:00.000Z"),
"days_of_validity": 10
}

我正在尝试查询所有文件

"creation_date" < today -  "days_of_validity"

这是我迄今为止的最大努力：

docs.find({"creation_date": 
{$lt:  new Date().setDate(new Date().getDate() - days_of_validity)}})

事情是，显然我不能将js函数与mongo字段混合。

关于如何解决这个问题的任何想法？

Answer 1

您还有另一个问题，即您尝试将一个字段与另一个字段进行比较：days_of_validity实际上并不是一个有效变量。您需要进行聚合。像这样：

db.post.aggregate([
    {"$project":{
        "creation_date":1,
        "earliest":{"$subtract":
            [ISODate(), {"$multiply":["$days_of_validity", 1000*3600*24]}]}}},
    {"$project": {"delta": {"$subtract":["$creation_date", "$earliest"]}}},
    {"$match":{"delta": {"$lt": 0}}}])

Answer 2

您好我尝试了更多的计算希望，这将有助于您

    db.collectionName.aggregate({
    "$project": {
    "crationTimestamp": {
        "$subtract": [{
            "$divide": [{
                "$subtract": ["$creation_date", new Date("1970-01-01")]
            }, 1]
        }, {
            "$mod": [{
                "$divide": [{
                    "$subtract": ["$creation_date", new Date("1970-01-01")]
                }, 1]
            }, 1]
        }]
    },
    "days_of_validity": "$days_of_validity",
    "todayTimeStamp": {
        "$subtract": [new Date().getTime(), 0]
    },
    "creation_date": "$creation_date"
    }
}, {
    "$project": {
    "dayDiff": {
        "$multiply": ["$days_of_validity", 24, 60, 60, 1000]
    },
    "todayTimeStamp": "$todayTimeStamp",
    "crationTimestamp": "$crationTimestamp",
    "days_of_validity": "$days_of_validity",
    "creation_date": "$creation_date"

    }
}, {
    "$project": {
    "todayAndDaysDiff": {
        "$subtract": ["$todayTimeStamp", "$dayDiff"]
    },
    "crationTimestamp": "$crationTimestamp",
    "days_of_validity": "$days_of_validity",
    "creation_date": "$creation_date"
    }
}, {
    "$project": {
    "finalDiff": {
        "$subtract": ["$crationTimestamp", "$todayAndDaysDiff"]
    },
    "days_of_validity": "$days_of_validity",
    "creation_date": "$creation_date"
    }
}, {
    "$match": {
    "finalDiff": {
        "$lt": 0
    }
    }
}, {
    "$project": {
    "days_of_validity": "$days_of_validity",
    "creation_date": "$creation_date"
    }
})

查询Mongodb时混合字段和js函数

2 个答案: