mongodb c# tutorial

Use MongoDB in C ++: Add Field{$ Set: {"field": 1 }})Delete Field{$ Unset: {"field": 1 }}) Query elements in an array{"Keyword": {$ all: ["location", "other"]} Add array elements (repeated elements are not added){"$ AddToSet": {"keyword": {"$ each": ["location", "other"]} Query by longitude and latitude (longitude at the beginning and latitude at the end)Sort from near to far{"Latitude and longitude": {

Tags: syn max ase var = = Element Group Res Godpublic static void Onquery_qxdata (String DBName, String tablename,string layername){if (ConnectionString = = null) oncreatedb ();Modatabase = Moclient.getdatabase (DBName);var collection = modatabase.getcollection{$group: {_id:{stationid: "$stationID", StationName: "$stationName"},timedata:{$max: "$TimeData"},evalue:{$last: " $eValue "} }}var group = new Bsondocument {{"_id", New bsondocument{{"StationID", "$stationID"},{"StationName", "$stationNa

Query.all ("name", "a", "B");//match array with multiple elementsQuery.and (Query.eq ("name", "a"), Query.eq ("title", "T"));//satisfy multiple conditions at the same timeQuery.eq ("name", "a");//equalsQuery.exists ("type", true);//Determine if key value existsQUERY.GT ("value", 2);//Greater Than >Query.gte ("Value", 3);//greater than or equal to >=Query.in ("name", "a", "B");//Includes all values specified, you can specify different types of conditions and valuesquery.lt ("value", 9);//Less tha

Description of the exceptionThere is an "article" class, which contains a "listIt is no problem to store an "article" type of object in a MongoDB database, but retrieving it from the database throws an exception like this:[InvalidOperationException: an instance of an abstract class could not be created. ]WorkaroundPreviously consulted with Magicdict on this issue, his approach was to refer to this post: http://www.cnblogs.com/zlp520/p/3921435.htmlI di

Today, using the MongoDB C + + driver, there was an error when compiling the connection, and the string_data.h of the 93-line Max macro is displayed, which is not itself called the Max macro, but instead calls theStd::numeric_limitsThis is to generate an error, by searching for a workaround (reference URL: http://blog.chinaunix.net/uid-17102734-id-2830143.html), enclose the function in parentheses to avoid

CentosInstallationMongoDB C + + dirver Objective: The picture can't be displayed, but the pictures are added later. Website address:https://www.mongodb.org/ Drive: https://docs.mongodb.org/ecosystem/drivers/?_ga=1.81586452.2024551820.1440643898 Download release version Official website Installation Tutorial Address:https://docs.mongodb.org/ecosystem/drivers/cpp/ Installation Environment centos-5.10-

MongoDB is a way of nosql (not just SQL). is a general designation of a database management system that differs from a traditional relational database.Nosql-represents more than just SQL-No declarative query language-No pre-defined pattern-key-value pair storage, column storage, document storage, graphics database-final consistency, not ACID properties-Unstructured and unpredictable data-Cap theorem-High performance, high availability and scalabilityM

To back up a database, Mongorestore-d db/path/to/back_up For example: mongodump-d Bookstore-o/data01/db_backup/ This command will dump all of the DB collectionrecover data from a backup folder Mongorestore-d Bookstore/data01/db_backup/bookstore Back up or reply to the specified collection onlytake the Statistics table in bookstore DB as an example mongodump-d bookstore-c Statistics-o/data01/db_backup/

MongoDB Linux InstallationDownload the latest version of MongoDB, download link: http://www.mongodb.org/dr/fastdl.mongodb.org/linux/mongodb-linux-x86_64-2.0.2.tgz/downloadEnter TAR–XZVF mongodb-linux-x86_64-2.0.2.tgz into the/usr/local/mongodb directory, the following is cal

is called, such as the following example, we will query the linked list first, and then sort:var filter = BuildersCasting on fieldsMany times we don't need all the data in the document, it's like in SQL we just select the data we need instead of all the fields in the table, and naturally mongodb can let me do it, we just have to use it like filtering and sorting. The Projection constructor is constructed and then passed to the Project method, and in

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"counter" in the data "counter" to 1 to 110:var filter = Buildersvar updated = Buildersvar result = collection. Updateoneasync (filter, updated). Result;If we need a batch update, we can call Updatemanyasync. For example, we need to add 100 to the "counter" in the data "counter" less than 10, so we can write like this:var filter = Buildersvar updated = Buildersvar result = collection. Updatemanyasync (filter, updated). Result;Delete a documentAs the base part, this is also the last part, using

- 1页数据 .Skip((index - 1) * size) // 选取一页数据 .Take(size) // 转换为集合 .ToListAsync();#endregion对内嵌数组的查询操作主要是通过聚合来实现，以上代码转换为Native方式后是以下命令。aggregate([ {"$match" : { "_id" : ObjectId("5aa877e4aa25752ab4d4cae3") } }, { "$unwind" : "$Records" }, { "$project" : { "Records" : "$Records", "_id" : 0 } }, { "$sort" : { "Records.RecorDateTime" : 1 } }, { "$skip" : 30 }, { "$limit" : 10 }]);If both System.Linq and MongoDB.Driver.Linq are referenced at the same time, the method ambi

Tags: framework delete HTM blog mod dem Technology returns MONGODBBecause of the need to write a generic-based helper, it is easier to use. For the sake of the people do not repeat the wheel, so sent to hope to help who. Complex queries are best used with LINQ, which is also the official advice of MongoDB.MongoDB's C # configurationThis part of a lot of articles are mentioned, it is necessary to note that the driver with your version of

comments, it is obvious that the latter performance is the former One-third, the gap is very large. The theory of skip efficiency is also proved.C # implementationThe statement and efficiency of MONGODB paging have been discussed above, so we can implement the C # driver version.The official Bson driver is used in this article, see Reference 4. The MONGO driver comes with another way, a native query like A

This article introduces briefly, using the official driver to operate MongoDB. As for the MongoDB native additions and deletions to change the statement, and so later to learn slowly.One, the operation of MongoDB Drive mainly have two1. Official driver: https://github.com/mongodb/mongo-csharp-driver/downloads, newer or

IOS getting started tutorial (III)-c language features, ios getting started tutorial-c features // 3. C language features // 3.1 Function Definition // function return type function name (parameter) {// dosomthing //} This is the general function definition, // there is an o

This course includes:"1" C language (1 months)"2" C + + syntax and data structure (1 months))"3" MFC project Development (1 months)"4" Linux project development (1 months)Previous sessions of the video have been uploaded to Baidu Network, please follow the video tutorial in advance to master the progress of the course.VS2015 Series Video tutorials include:"VS2015

This 2 days learning mongodb3.2.9, the user set up, the results in C # query when the error, to see the literal meaning of the user verification did not pass, but I use the shell is completely no problem, and then the Internet search, found that I used the old driver, the old driver is the old check mode, And mongodb3.2.9 is using the new scram-sha-1 check, so the verification will not passMy side because of the software environment problems and want

1. Have not previously used C # to develop the corresponding desktop applications, now that you want from zero to have to develop, naturally need to master the C # Desktop development related principles and techniques, MongoDB has the production of meaningful data management operations, and a database management software product which is developed by many types o