bson

问题 I want to hack ObjectId by manipulating the machineId like this: <timestamp> <machineId> <processId> <inc> UserId XXXXXXXX XXXX01 XXXX XXXXXX OrderId XXXXXXXX XXXX02 XXXX XXXXXX CardId XXXXXXXX XXXX03 XXXX XXXXXX ... the basic idea is to use 1 byte of machineId to distinguish the object type, my question is: is there any problem when doing so (considering uniqueness and sharding)? --- update on Dec 9 --- Due to the difference between the spec and implementation Why the bson java

问题 I am trying to pass a multiple sort query to the "Sort" parameter of the mgo package (see https://godoc.org/labix.org/v2/mgo#Query.Sort). If the parameters are dynamic (currently held in a slice), how can I translate that into a valid sort string. A working example would be: db.C(Collection).Find(Query).Limit(limit).Sort("-created_when", "-title").Iter() But if "-created_when" and "-title" are held in a slice, and I try using a slice join like: sortBy := []string{"-created_when", "title"} db

问题 It is kind of stupid syntax error, tried tons of ways, just couldn't get it work, someone please help. MongoDB in Go with mgo , I just tried to simplify use the $ne operator, code like below, but kept getting compile syntax error: line 15: convIter := Session.Copy().DB("").C("convs").Find(bson.M { line 16: "conversationStatus": interface{} { line 17: bson.M { line 18: "$ne": "DESTROYED" line 19: }, line 20: }, line 21: }).Iter() Tried to add comma , remove comma everywhere, just couldn't get

问题 Reading through the BSON specification I came across the terminal and non-terminal terms in it. For example: Valid BSON data is represented by the document non-terminal . <...> The following basic types are used as terminals in the rest of the grammar. What do “terminal” and “non-terminal” mean in the context of the BSON specification? 回答1: In formal grammar, a terminal symbol is one that cannot be broken down further, e.g. a literal character or digit (but not necessarily as it depends on

问题 Reading through the BSON specification I came across the terminal and non-terminal terms in it. For example: Valid BSON data is represented by the document non-terminal . <...> The following basic types are used as terminals in the rest of the grammar. What do “terminal” and “non-terminal” mean in the context of the BSON specification? 回答1: In formal grammar, a terminal symbol is one that cannot be broken down further, e.g. a literal character or digit (but not necessarily as it depends on

问题 I currently have a project that's being migrated away from Parse Server but needs to maintain backwards compatibility. Since Parse Server generates it's own object Ids, rather than using Mongo's I'd like to know: How does Parse Server generate it's objectIds? and why does it do this when MongoDB has great objectId generation natively? Will parse be able to work with objects with non-Parse generated IDs? An example: _id: "LvIzxv5spL" // created by Parse Server _id: "507f1f77bcf86cd799439011" /

问题 Problem with find Date from Node to MongoDB: It's been said MongoDB might not be storing a Date object, but a string, but I'm not sure how to check, or how to fix that. In my turnys.js file: exports.findNeededTurnys = function(req, handler) { console.log("findNeededTurnys"); var key; //var arg0 = {$or:[{start:{$lte:new Date()}, $where: "this.users.length == this.seats"}]}; var arg0 = {start:{$lte:new Date()}}; console.log("findNeededTurnys: arg0="+JSON.stringify(arg0)); turnydb.collection(

问题 Problem with find Date from Node to MongoDB: It's been said MongoDB might not be storing a Date object, but a string, but I'm not sure how to check, or how to fix that. In my turnys.js file: exports.findNeededTurnys = function(req, handler) { console.log("findNeededTurnys"); var key; //var arg0 = {$or:[{start:{$lte:new Date()}, $where: "this.users.length == this.seats"}]}; var arg0 = {start:{$lte:new Date()}}; console.log("findNeededTurnys: arg0="+JSON.stringify(arg0)); turnydb.collection(

问题 In my app I'm letting mongo generate order id's via its ObjectId method. But in user testing we've had some concerns that the order id's are humanly 'intimidating', i.e. if you need to discuss your order with someone over the telephone, reading out 24 alphanumeric characters is a bit tedious. At the same time, I don't really want to have to store two different id's, one 'human-accessible' and one used by mongo internally. So my question is this - is there a way to choose a substring of length

问题 Using spark 1.6.0 Say i have a class like this case class MyClass(date: java.util.Date, oid: org.bson.types.ObjectId) if i have //rdd: RDD[MyClass] rdd.toDF("date", "oid") i get java.lang.UnsupportedOperationException: Schema for type java.util.Date/org.bson.types.ObjectId is not supported now i know i can make it a java.sql.Date but let's say MyClass is depended upon in too many other places to make that change everywhere, that still won't solve the ObjectId problem. i am also aware of the