![]() Most typical reference in MongoDB document works exactly like foreign keys in relational databases – field in one record (1) references record in another record (2). Document References (Many-to-One) - AKA Foreign Keys References are the same concept as in the case of relational databases – a data normalization technique where row in one set references row in another (or the same). On the diagram, just as in the case of embedded document, it is represented as a hierarchy within an entity. #Dbschema mongodb design movieExample below shows one Movie record having a list of actor records.Īs in the case of embedded document Dataedo shows such relationship as hierarchy of fields, except in this case type of parent field is Document (array of documents) instead of Document. In this case one parent record is related to multiple child record. More complex design is the implementation of one-to-many relationship as embedded array of documents. On the diagram it is represented as a hierarchy in the entity.Įmbedded Array of Documents (One-to-Many) In case below, (Hollywood) Studio has embedded one headquarters record.ĭataedo shows this relationship as a hierarchy of fields in collection entity. One parent record is related to one child record. Embedded Document (One-to-One)īasic embedded document is a one-to-one relationship. It is defined directly in data and you can view those relationships in Dataedo right after schema import. And this is where Dataedo shows its value – you end up with additional information about data (metadata) that cannot be easily obtained by people working with data.ĭiscovering Embedded Documents RelationshipsĮmbedded documents are specific to semi-structured data – ability to embed another record (document), or array of rows, into another record. References are logical, and as such, cannot be derived from data and needs to be documented manually in Dataedo.Embedded documents are nested in the data and can be discovered and visualized automatically.MongoDB, or any document store, has in general two categories of relationships – embedded documents and references. Let’s have an overview of relationships in this kind of databases. However, we can stretch the concept to fit JSON documents. MongoDB is not a relational database, it is a document store, so traditional ER modeling does not apply. It is a bit more complicated (as always) with the relationships. Dataedo discovered entities and their fields. To create an ER diagram, you need entities (collections) and relationships. When it finishes it creates complete data dictionary for your MongoDB database – list of collections and their attributes organized into hierarchy (documents, fields, arrays, etc.).ĭiscovering and Documenting Relationships samples documents in collections, parses the JSON documents, andĪnd builds data dictionary from that information.When you confirm, Dataedo will perform automatic schema discovery. You can choose collections to import from this list, but you just want to skip this step with Next to import entire schema. Dataedo will connect to your MongoDB database and list collections. When you provide connection details and click Connect. Click it, it will get copied into connection field. If you used MongoDB Compass to connect to your MongoDB instance you will find it in Recents section. If you don’t have it you can ask your admin, developers or anyone who might know. To connect to database click Add in the ribbon and choose Database connection option.Īnd connection type - Values or Connection string. Now that you have installed and configured Dataedo you can connect to your instance of MongoDB. Connect to MongoDB and import Collections File is just a document you can save anywhere. It is more advanced option for multi user environments so if you can’t get your hands on an instance go with the file option. Database is regular SQL Server or Azure SQL database. Repository is a file or database that will hold all the metadata. #Dbschema mongodb design installDifferent relationship types in MongoDB - embedded documents and referencesįirst, you need to download and install Dataedo Desktop on your computer. #Dbschema mongodb design pdf
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