The data in the collection is as follows: { _id: ObjectId(7df78ad8902c) title: MongoDB Overview , description: MongoDB is no sql database , by_user: runoob.com , url: http: www.runoob.com , tags: [ mongodb , database...
problem description has the following data structure: {id:1, name: "apple", alias:"", price: 5, type: "add"} {id:1, name: "apple", alias:"", price: 3, type: "minus"} {id:1, name: "pear&...
if the collection test has the following document format { "_id" : ObjectId("123456"), "name" : "test", "body" : [ { "hash" : &q...
when you associate with mysql, you can use id to associate, and you can store two tables during the same database operation. Because the primary key id can be self-increasing and is not affected by other factors, the two tables can be associated with id,...
error message: PHP Fatal error: Uncaught MongoDB Driver Exception RuntimeException: Invalid reply to find command. in ... library MongoDB Operation Find.php:299 Stack trace: -sharp0 ... library MongoDB Operation Find.php(299): MongoDB Drive...
students are doing a Wechat mall store, because there are different goods, each commodity has different attributes, that is, the attributes are not fixed. I have considered whether it is reasonable to design in this way: { -id: , name: , d...
{% for item in list %} <li onclick="edit(item._id)" data-id=""> <p class="content">{{ item.title }} <p class="date">{{ item.createdAt }} < li> {% endfor %} as in the previous c...
use mongoimport to import data in json format. After the import is successful, the data in the collection is in the wrong order, and the cause of the problem has not been found. related codes original data and imported data {"_id":{&qu...
in mongoose, you need to define schema, to insert a database. Here is a problem: how do I read a value that is not a table I created? here is the code related codes Please paste the code text below (do not replace the code with pictures) w...
problem description two Collection: teams , scores . teams score is an Array, field associated with _ id . now look up teams and count the score according to its round field. but I can only look up all the relevant values from scores ...
problem description I want to update a field in the subdocument array, which has been written according to the official document but cannot be updated. Please take a look at it. Thank you! related codes Update method: modle.updateOne({ "...
problem description pymongo cannot connect to the mongo cluster, even locally is fine. everything is fine on the command line. the environmental background of the problems and what methods you have tried Local mongo has no authentication, but the...
delete the historical data in the table and retain only the data of the most recent quarter before deletion "count" : 1379345, -sharp "size" : 3823247286, -sharp "nindexes" : 4, "totalIndexSize" : 86913024, -...
question looking at mongodb s slow query log, it is found that there are many count slow queries, the longest of which is half a minute . solution I don t want to add a lot of indexes (such as article title, article platform, account emotio...
problem description how do I insert an array into Collection? If item_id exists, do not insert? for example: item_arr = [ { item_id : 1 , title : AAA }, { item_id : 2 , title : BBB } ] I would ...
{ "_id" : { "$oid" : "5b8e1d485d30a6499820cfc5" }, "id" : 5, "lessonCount" : 5, "userCount" : 6, "users" : [{ "phone" : "1301111000", &q...
I execute the first command: db.runCommand({"enablesharding":"yuncaitest"}) Tip: sharding already enabled for database yuncaitest indicates that the sharding cluster has been enabled for this database. when I set a collection a...
this.find({}).populate({ path: userId , match: {name: 123123x } }).exec(callback); the associated query of two tables, and how to make the whole data not return when there is no data in the associated table ...
just installed mongodb 4.0.2, you can view the default database normally: > show dbs admin 0.000GB config 0.000GB local 0.000GB but importing bson data shows an error: > mongorestore -h localhost:27017 -d test D: wnmp www project_name ...
the, WiredTiger internal cache with 1G memory on the server should occupy 256m., WiredTiger internal cache Mongo startup will put the data and index in the system cache filesystem cache., filesystem cache belongs to the system idle memory. What is the ro...
now there is a requirement to send API requests in batches, and the number is a bit large. When the web page opens, it will prompt an error soon, because too many requests sent at the same time will be timed out if some of the requests are not sent and ...
mapActions using vuex storeaction const actions = { setLoginInfo ({ commit }, data) { localStorage.setItem( loginStatus , true) commit( SET_LOGIN_STATUS , true) }, setGwShopUserToken ({ commit }, token) { localStorage.setItem( ...
situation if you leave in the middle of the month and immediately enter the next company, the two sides will deduct tax according to their own wages, instead of stacking them together. For example, the last company paid 5000 in half a month, and accor...
1. Problem description 1.1 problem description when CPP11 creates a child thread, it uses the class as a parameter. Although only one child thread is created, the copy constructor is called many times, which is counterintuitive, cannot be explained,...
now the development uses seajs, used by vue, and some API, of ES6 is used in the project code. Now there are some problems in online compilation: online compilation generated on the right, there will be some dependencies in it, I directly copy the ...