Tags: text cts rdb ted xxxxx BMS Find xxx MonMongoDB versus RDBMS Where statement comparison
Operation
format
Example
similar statements in an RDBMS
Equals
{}
db.col.find({"by":"XXXX"}).pretty()
where by = ‘XXXX‘
Less than
{
db.col.find({"likes":{$lt:50}}).pretty()
where likes
Less than or equal to
{
db.col.find({"likes":{$lte:50}}).pretty()
where likes
Grea
Today in the project encountered about MongoDB nested query, has not been contacted before, query the relevant data to record the results.
The data in the MongoDB are as follows:
> Db.customer.findOne ()
{
"_id": ObjectId ("57636c8e35defe029962107e"),
"_class": " Com.bu2trip.ticket.model.Customer ",
" name
Show DBS: Displays all local databases. That is, the local MongoDB database, which holds all databases under the folder of the database. Use TestDB: Using the TestDB database. This is the only way to use show collections, db. Userinfo.find ({}). Pretty (), DB. Userinfo.findone () command, otherwise you will not be sure of the database that is queried.Show Collections: Displays all the collections and collection in the specified database.Db. Userinfo.f
Http://www.cnblogs.com/viprx/archive/2012/09/06/2673693.htmlThe basic syntax for MONGODB conditional queries.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
Label:Original link http://www.oschina.net/question/12_59707 monjadb is a mongodb GUI client tool that provides intuitive MONGODB data management capabilities that support Windows/mac/linux.MONJADB is an Eclipse plugin, you must first install eclipse. Main Features:
Use
WYSIWYG Edit Json/table/tree Data
Very flexible form Management
"Action
embedded objects
Db.postings.find ({"Author.name": "Joe"});
Note that usage is author.name, just use one point. More detailed can see this link: dot notation
As an example:
> Db.blog.save ({title: "My first Post", Author: {Name: "Jane", Id:1}})
If we want to query authors name is Jane, we can do this:
> Db.blog.findOne ({"Author.name": "Jane"})
If not, then you need to use the following sentence to match:
Db.blog.findOne ({"Author": {"name": "Jane",
()) {User user = new user ();
User.parse (Find.next ());
SYSTEM.OUT.PRINTLN (user); }} public static void Main (string[] ArGS) {Userdao Userdao = new Userdao ();
Userdao.query (); }
Queryoperators class source code:
Queryoperators.java/** * Copyright (C) 10gen Inc.
* Licensed under the Apache License, Version 2.0 (the "License");
* You could not use this file, except in compliance with the License. * Obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * *
Mongodb uses fuzzy search and $ type for recent monitoring services. Because non-numeric data is collected, the monitoring charts cannot be displayed normally. Therefore, you need to find and delete the data, the developer then corrects the data inserted into the database from the source and no longer produces non-numeric content. The following is an example: Create test data: for (i1; i100; I ++
Mongodb us
of a lot of data count is 1,that is {"match": {"Count": {"GT": 2}}; failure, why?4, back up the first before deleting.Backup /usr/local/mongodb/mongodb-linux-x86_64-2.4.4--30000-d-c paymentinfo -o /home/backup/mongodb_pos_paymentinfo_3.txt5, start loop DeleteHere DS is a large result set, directly with Ds.result can get the result set inside the packet query ou
After reading some information, I only need to know how to query and use MongoDB. This is enough.
On the left is the MongoDB query statement, and on the right is the SQL statement. It is easy to use.
DB. Users. Find () Select * from users
DB. Users. Find ({"Age": 27}) Select * from users where age = 27
DB. Users. Find
This is a creation in
Article, where the information may have evolved or changed.
Golang mongodb MgO Insert, query a small example, Golang still give me that feeling, than Nodejs write up comfortable. Package main import ("FMT" "Launchpad.net/mgo" "Launchpad.net/mgo/bson") type Mail struct {Id Bson. ObjectId "_id" Name string Email String} func Main () {//Connect to database session, err: = MgO. Dial ("127.
Conditions similar to: a=5 or (a=2 and b>3)Basicdblist endlist = new Basicdblist ();Basicdbobject forceend = new Basicdbobject ();Forceend.put ("status", 5);Basicdblist condlist = new Basicdblist ();Basicdbobject autoend = new Basicdbobject ();Condlist.add (New Basicdbobject ("status", 2));Condlist.add (New Basicdbobject ("EndTime", New Basicdbobject ("$lt", New Date ()));Autoend.put ("$and", condlist);Endlist.add (Forceend);Endlist.add (Autoend);Basicdbobject.put ("$or", endlist);A compound
Query.all ("name", "a", "B"), or//through multiple elements to match the array Query.and (Query.eq ("name", "a"), Query.eq ("title", "T"));//satisfy multiple conditions at the same time query.eq ("name", "a");//equals Query.exists ("type", true);//Determines whether the key value exists query.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 val
Label:Read some information, corresponding only need to know how to query and use MongoDB for me, these are enough. On the left is the MONGODB query statement, and the right is the SQL statement. Compared with the use, very convenient. Db.users.find () SELECT * from Users Db.users.find ({"Age": +}) SELECT * from the us
Tags: JSON it's equality function database query collection size block MONGO3.4.2 Data Query In the MongoDB database, the support for database queries is in place, with relational operations, logical operations, array operations, and regular operations. For the query operation core syntax for data:
Db. Collec
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