MongoDB数据库使用举例

方法一：

db.serverStatus().repl

{
    "hosts" : [
        "10.1.61.100:27017"
    ],
    "setName" : "whale-repl",
    "setVersion" : 1,
    "ismaster" : true,                 # ismaster 为 true  表示当前节点是主节点
    "secondary" : false,
    "primary" : "10.1.61.100:27017",   # primary 指示主节点的地址
    "me" : "10.1.61.100:27017",
    "electionId" : ObjectId("7fffffff0000000000000004"),
    "lastWrite" : {
        "opTime" : {
            "ts" : Timestamp(1590632976, 1),
            "t" : NumberLong(4)
        },
        "lastWriteDate" : ISODate("2020-05-28T10:29:36.000+08:00"),
        "majorityOpTime" : {
            "ts" : Timestamp(1590632976, 1),
            "t" : NumberLong(4)
        },
        "majorityWriteDate" : ISODate("2020-05-28T10:29:36.000+08:00")
    },
    "rbid" : 1
}

db.resObject.find({
        _id: ObjectId("60f54bf1b70544c867446211")
    })
    .sort({
        _id: -1
    })
    .limit(100)

db.resObject.find({"classCode":"link",
    "attrValues.srcNodeID.V":"60f54bf1b70544c867446211" 
})
   .projection({})
   .sort({_id:-1})
   .limit(100)