how to query mongodb in java

MongoDB Java driver is thread-safe, for general applications, as long as a MONGO instance, MONGO has a built-in connection pool (pool size defaults to 10). The following code gives you an introduction to the Java-driven operations of MongoDB, as shown in the following code: Import java.util.ArrayList; Import java

The content of the Pom.xml in HelloWorld's MAVEN project is But what if you want to refer to a third party's library development? This article discusses this issue, taking MongoDB as an example, here does not introduce MongoDB, only know that he is a nosql, and there are client and server, We will refer to MongoDB Library to realize

. Let's imagine a simple SQL self-defining function such as the following: function AddNumbers (x, y) {return x + y;}Here we convert this SQL-defined function into MongoDB's stored procedure: > Db.system.js.save ({_id: "AddNumbers", Value:function (x, y) {return x + y;}});: 2: Querying Stored ProceduresStored procedures can be viewed, changed, and deleted, so we use find to see if the stored procedure has been created. > Db.system.js.find (){"_id": "AddNumbers", "value": Function cf__1__f_ (x, y

("cust_id")]Public string CustomerId {get; set ;}/// /// Total/// [BsonElement ("amount")]Public int Amount {get; set ;}/// /// Status/// [BsonElement ("status")]Public string Status {get; set ;}} For the following operations based on the MongoDB GUI tool, see references 3.First, let's take a look at the parameters and results required for paging. The common parameters required for paging are:PageIndex current pageP

MongoDB uses find to query, returning a subset of the documents in a collection;Returns all documents in the Document collection blog:> Db.post.find () {"_id": ObjectId ("54a530c3ff0df3732bac1681"), "id": 2, "name": "Joe", "age": +, "sex": 1, "SCHool ":" Marry "} {" _id ": ObjectId (" 54a530c3ff0df3732bac1680 ")," id ": 1," name ":" Joe "," age ": +," comments ": [ "Test2", "Test9", "Test5"], "sex": 1, "sch

MongoDB slow query record in MySQL, the slow query log is often used as the basis for us to optimize the database, is there a similar function in MongoDB? The answer is yes, that's MONGO database. Profiler. Not only, but there are some more detailed information than the MySQL slow

Description: The optimization case is to express the meaning of the individual parameters, combining the analysis of the business with the logical implementation, and how to create the index and column order is selected (no longer described here)Environment Description :MongoDB version 3.0.9, replica set 3 node, memory 64g,cpu core, disk 2TB SSD, using WT storage engine ...The amount of data in this table is more than 260 million.The general analysis

This article is a blog post from MongoDB core developer @ kchodorow. It is the first article about MongoDB query puzzles. It introduces some query rules and usage of range query in Array through several examples. Assume that a Collection contains the following data: {x:-5} {

On the blog discussed, the database query data returned to the foreground JSP. The blog mainly uses Ajax calls to display a JSON string to get one of these fields, assigned to one of the controls in the interface. That this blog, we explain, the backstage list pass JSP display. List delivery interface, what we used to do in the past. A foreach El expression. or Java code. So how do you show the list in JSON

->selectdb (' MyDB ')->selectcollection ("User"); Echo $dbCount(); ? > Operation result is: 3 6, or operation of the query When querying, we may also use the or operation. The syntax format is as follows: $db->find (Array (' $or ' = = Array (' id ' = ' 1 '), Array (' name ' = ' java '))); For example above, our query ID is 1, or name is