使用聚合合并两个集合

Question

我的mongodb中的JSON数据，包含集合名称和查询

db.getCollection('UserCompanyDetails').find({})

示例输出：

{
    "_id" : ObjectId("5885d3d99aa060de0b8b4569"),
    "CompanyEmailId" : "punnamadhu@gmail.com",
    "CompanyPassword" : "1eb1f47fc0e5603966a6d2e7142724f5",
    "CompanyContact" : "9666999011",
    "CompanyName" : "Madhu",
    "ContactPersonName" : "Madhu",
    "CompanyAddress" : "hyderabad",
    "CompanyState" : "",
    "CompanyCountry" : "",
    "CompanySpecilizations" : [ 
        "5869edb837478d6018b7dfac", 
        "5869edb937478d6018b7dfaf"
    ],
    "CompanyStatus" : NumberLong(1),
    "CompanyOtpStatus" : NumberLong(1)
}

另一个名为

的集合

db.getCollection('UserIdOtp').find({})

示例输出：

/* 1 */
{
    "_id" : ObjectId("587cc76a9aa060a5138b456b"),
    "otp" : "946170",
    "userID" : "587cc76a9aa060a5138b456a",
    "otpStatus" : NumberLong(0)
}

/* 2 */
{
    "_id" : ObjectId("587cc7f19aa0600e068b456d"),
    "otp" : "261743",
    "userID" : "5885d3d99aa060de0b8b4569",
    "otpStatus" : NumberLong(0)
}

/* 3 */
{
    "_id" : ObjectId("587cc9349aa06082288b456b"),
    "otp" : "197305",
    "userID" : "587cc7f19aa0600e068b456c",
    "otpStatus" : NumberLong(0)
}

所以我想用聚合来合并这两个集合，我该怎么做呢？