![dbschema mongodb design dbschema mongodb design](https://www.mongodb.com/developer/images/article/schema-design-best-practices/relational-user-model.png)
In the MongoPreparedStatement we start a Rhino JavaScript engine, and pass this query to the engine.
Dbschema mongodb design driver#
The driver implements a PreparedStatement where native MongoDb queries can be passed.
![dbschema mongodb design dbschema mongodb design](https://i0.wp.com/shumailapc.com/wp-content/uploads/2021/03/60284259.png)
We are looking forward to improve this and make possible to execute all MongoDb native queries via JDBC. ResultSet rs = statement.executeQuery( query ) Īny contributions to this project are welcome. Statement statement = con.createStatement() String query = "db.sampleCollection().find()" OTHER URL (SAME AS FOR MONGODB NATIVE DRIVER): mongodb://,:2500/?replicaSet=test&connectTimeoutMS=300000 Properties.put("password", "somepassword" ) Ĭonnection con = DriverManager.getConnection("jdbc:mongodb://host1:9160/keyspace1", properties) Properties properties = new Properties() Unpack and include all jars in your classpath.
Dbschema mongodb design download#
Download JDBC Driver Binary DistributionĪvailable here. The number of scanned documents can be set in the URL using the parameter scan=.įor any improvements please create merge requests to this repository. Scanning random documents from each collection. We presume that collections are storing similar documents, so we 'deduce' a virtual schema by To be able to execute native MongoDb queries we embedded an Rhino JavaScript engine inside the driver.Įach time you execute a query we parse and run it as JavaScript with Rhino.Ĭalling methods from the DatabaseMetaData.getTables(), getColumns(), etc., the driver willĭeduce a logical structure of the database. This because the first document in the result may have less keys as the next records. If expand is set the driver will read ahead a number of rows in order to create a correct ResultSetMetaData. Use resultSet.getObject(1) to get this object.Īdding the parameter expand=true in the URL will create a column in the result set for each key in the result document. The driver returns by default a ResultSet with a single Object. Therefore the JDBC URL is the same as MongoDb URL. The driver is using the native MongoDb Java driver to connect and execute queries. JDBC driver capable to execute native MongoDb queries, similar with Mongo Shell. The driver is written by DbSchema - MongoDb Diagram Designer for everybody how needs an MongoDb JDBC driver. The virtual foreign keys are saved in the DbSchema project file.MongoDb JDBC Driver | DbSchema MongoDB Designer The line between collecitons is a virutal relation, meaning the ref field is poiting to the master collection.
![dbschema mongodb design dbschema mongodb design](https://hackolade.com/img/schema-visualization.jpg)
Refresh the schema as in the chapters before to get the collection into the diagram. You can copy-paste this in DbSchema and execute it. The next collection slave has a field ref as the _id of one of the master documents.
Dbschema mongodb design code#
Here is a JSON document: () This code is creating a collection master with name and position. For detailed instructions please read the DbSchema SQL tutorial from To list the hobbies for each person we have to execute:ģ SELECT p.firstname, p.lastname, ph.hours_per_week, h.hobbyname FROM sample2.persons p INNER JOIN sample2.person_hobbies ph ON (p.personid = ph.personid) INNER JOIN sample2.hobbies h ON (ph.hobbyid = h.hobbyid) And the result: In MongoDb the data can have a hierarchical structure, called JSON. You can execute the script above in DbSchema SQL Editor, refresh the schema and get the diagram bellow. In our case we have created three tables: one for persons, one for hobbies and one which stores each person hobby. Each table has a predefined structure as part of the schema. In MySql we will execute CREATE TABLE PERSONS( personid integer primary key, firstname varchar(100), lastname varchar(200) ) CREATE TABLE HOBBIES( hobbyid integer primary key, hobbyname varchar(100) ) CREATE TABLE PERSON_HOBBIES( personid integer not null, hobbyid integer not null, hours_per_week integer, constraint fk1 foreign key( personid ) references persons(personid), constraint fk2 foreign key( hobbyid ) references hobbies(hobbyid) ) Insert into persons (personid, firstname, lastname) values (1,'John', 'Steven') Insert into hobbies (hobbyid, hobbyname) values (1, 'Tennis') Insert into hobbies (hobbyid, hobbyname) values (2, 'Swimming') Insert into person_hobbies (personid, hobbyid, hours_per_week) values (1,1,5 ) Insert into person_hobbies (personid, hobbyid, hours_per_week) values (1,2,3 ) SQL databases are table-oriented. We will store in MySql and MongoDb a list of persons with their hobbies. 2 MySql vs MongoDb I will explain the difference between SQL databases and NoSQL with a practical example.