All data exists in BSON (similar JSON) Mongdb format, the set may be stored, map, binary files, and other data types.
Common database operations
use [database name]; // have to select, add and select not to
show dbs; // query all database list
db; // view the current library
db.dropDatabase (); // delete the current library;
Common set of operations
show collectoins; // set of all queries in the current library;
Show the Tables; // is the set of all queries in the current library;
. DB [collection name] .drop (); // set to delete the specified name;
DB [collection name] .insert ({});. // if the presence of the collection, will create and add data.
Common Operations for the
. DB [collection name] .insert ({}); // add the data set for the specified name;
DB [collection name] .insertOne ({});. // add a data set for the specified name;
DB [collection name. ] .insertMany ({}); // add to the set of a plurality of data specified name;
DB [collection name] .find ();. // query specifies a set of all the data;
DB [collection name] .findOne ();. / / query specifies the first data set exists;
DB [collection name] .findAndModify ();. // query and modify all data
DB [collection name] .findOneAndDelete ();. // first check out the compliance data condition and delete
db [collection name] .findOneAndReplace ();. // query the data in line with the conditions of the first and replace
db [collection name] .findOneAndUpdate ();. // check out the first qualifying and modify data
. db [collection name] .deleteOne (); // delete a qualified data
db [collection name] .deleteMany ();. // delete the data meet the requirements of multiple
db [collection name] .update ().; // modify a set of qualified data
DB [collection name] .updateOne ();. // modify data that meets a set of criteria
DB [collection name] .updateMany ();. // modify the set of all qualified data
Queries operator:
Gt greater than $, $ lt less than, greater than or equal GTE $, $ lte less.
db.test.find({"t":{"$gt":10}});
db.test.find({"t":{"$lt":10}});
db.test.find({"t":{"$gte":10}});
db.test.find({"t":{"$lte":10}});
Modify the operator needs to be added when the document:
$inc
The value of this field based on the value to be added incrementally.
db.test.update ({ "a": "d"}, { "$ inc": { "t": 2}}); // field of numeric type can be used
$ i
Value is multiplied by the value of the specified field
db.test.update ({ "a": "d"}, { "$ mul": { "t": 3}}); // field of numeric type can be used
$rename
Renaming Fields
db.test.update({"a":"d"},{"$rename":{"a":"b"}});
$ setOnInsert
In operation, the operation assigned to the corresponding field
// When the data when the condition is not detected, the add operation, the value will be performed after the $ setOnInsert, provided that the parameters set for upsert to true
// When the data already exists in isolated conditions, will perform $ set after the statement
// $ setOnInsert use $ set together under normal circumstances.
db.test.update({"a":"d"},{"$setOnInsert":{"as":"df"},"$set":{"zzx":"sdf"}},{"upsert":"true"});
$set
To specify the value of a bond, if it does not exist, create
db.test.update ({ "a": " b"}, { "$ set": { "a": "c"}}); // all the values of a = b to a C; If there are a plurality find qualified, will modify the first data to be inserted;
db.test.update ({ "a": "B"}, { "$ SET": { "Time": ISODate ( "2019-11-12 12:34:56")}}); // add time field
$unset
To specify the value of a bond, if it does not exist is not created created
db.test.update ({ "a": "b"}, { "$ unset": { "a": [arbitrary parameter]}}); // delete the specified field is understood to mean
$
Only when smaller than the conventional field values specified update the field.
db.test.update ({ "z": " s"}, { "$ min": { "t": 14}}); // must be completed with a value less than the stored value to be updated;
$max
Only when the value is greater than the current specified field values to update the field.
db.test.update ({ "z": " s"}, { "$ max": { "t": 14}}); // must be completed with a value greater than the stored value to be updated;
The basic operation of the java Mongdb
Necessary to introduce the following jar package
1. Connect mongodb
// initialize mongdb database, mongdb default port is initialized 27017
public class the DataBase { Private static MongoClient mongoClient; static { System.out.println ( "MongoDB initialization" ); IF (mongoClient == null ) { mongoClient = new new MongoClient ( "localhost ", 27017 ); } } }
2. Connect the following specified collection specified database
public static MongoCollection<Document> getCollection(String dbName, String collName) { if (null == collName || "".equals(collName)) { return null; } if (null == dbName || "".equals(dbName)) { return null; } MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName); return collection; }
3. Follow
Add (insertOne can be replaced insertMany ())
MongoCollection<Document> collection = getCollection(dbName, collName); Document param = new Document(); param.put("a", "b");
param.put("c", "d");
collection.insertOne(param);
Modification (updateOne updateMany can be replaced or findOneAndUpdate)
MongoCollection<Document> coll = getCollection("test", "login");
Document test = new Document();
test.put("a","v");
test.put("b","z");
coll.updateOne(test, new Document("$set",new Document("role","user")));
Delete (deleteOne can be replaced deleteMany or findOneAndDelete )
MongoCollection<Document> collection = getCollection(dbName, collName); Document param = new Document(); param.put("a", "b"); param.put("c", "d"); collection.deleteONe(param);
Inquire
MongoCollection<Document> collection = getCollection(dbName, collName); Document param = new Document(); param.put("a", "b"); param.put("c", "d"); FindIterable<Document> find = collection.find(param); MongoCursor<Document> iterator = find.iterator(); while (iterator.hasNext()) { Document next = iterator.next(); System.out.println(next); }