I want download data from a Rest API into a database.The data I want save are typed objects, like java object. I have chosen cassandra because it support the type Array type, Map type, versus standard SQLdatabase(Mysql, Sqlite,..). It is better to serialize java object.
In first, I should create the tables CQL from json schema of REST API. How it is possible to generate CQL table from json schema of REST API.
I know openapi-generator can generate mysql schema from json schema, but don't support CQL for the moment. So I need to search a alternative solution.
I haven't used off-the-shelf packages extensively to manage Cassandra schema but there are possibly open-source projects or software like Hackolade that might do it for you.
https://cassandra.link/cassandra.toolkit/ managed by Anant (I don't have any affiliation) has an extensive list of resources you might be interested in. Cheers!
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I was created my project in spring 4 MVC + Hibernate with MongoDB. now, I have to convert it into the Hibernate with MySQL. my problem is I have too many collections in MongoDB the format of bson and json. how can I convert that file into MySQL table format? is that possible?
Mongodb is a non-relational database, while MySQL is relational. The key difference is that the non relational database contains documents (JSON objects) which can contain hierarchical structure, where as the relational database expects the objects to be normalised, and broken down into tables. It is therefore not possible to simply convert the bson data from MongoDB into something which MySQL will understand. You will need to write some code that will read the data from MongoDB and the write it into MySQL.
The documents in your MongoDB collections represent serialised forms of some classes (POJOs, domain object etc) in your project. Presumably, you read this data from MongoDB deserialise it into its class form and use it in your project e.g. display it to end users, use it in calculations, generate reports from it etc.
Now, you'd prefer to host that data in MySQL so you'd like to know how to migrate the data from MongoDB to MySQL but since the persistent formats are radically different you are wondering how to do that.
Here are two options:
Use your application code to read the data from MongoDB, deserialise it into your classes and then write that data into MySQL using JDBC or an ORM mapping layer etc.
Use mongoexport to export the data from MongoDB (in JSON format) and then write some kind of adapter which is capable of mapping this data into the desired format for your MySQL data model.
The non functionals (especially for the read and write aspects) will differ between these approaches but fundamentally both approaches are quite similar; they both (1) read from MongoDB; (2) map the document data to the relational model; (3) write the mapped data into MySQL. The trickiest aspect of this flow is no. 2 and since only you understand your data and your relational model there is no tool which can magically do this for you. How would a thirdparty tool be sufficiently aware of your document model and your relational model to be able to perform this transformation for you?
You could investigate a MongoDB JDBC driver or use something like Apache Drill to facilitate JDBC queries onto your Mongo DB. Since these could return java.sql.ResultSet you would be dealing with a result format which is more suited for writing to MySQL but it's likely that this still wouldn't match your target relational model and hence you'd still need some form of transformation code.
ABAP Databases, oracle, MaxDB et al., are mostly RDBMS. Right now, I have a JSON structure that cannot be normalised and hence I want to store it as is. So, I want a MongoDB like Object store in ABAP.
What's the best way to achieve this? Is data cluster an option? Perhaps the only option?
I don't think you can connect to some other then supported DBs directly from ABAP. If you have Netweaver Java, you can call some custom Java application, which accesses MongoDB. You can check SAP Hana if there is something similar.
In ABAP you interact with RDBMS via ABAP Dictionary.
It supports data types like LCHR, STRING, RAWSTRING. Checkout docs for more details.
Data cluster is one option, but you can simply use a binary type DB field for storing the JSON data.
There is a method called transformation in ABAP, which converts from ABAP data to XML/JSON data and vice-versa.
There's a simple example on the following blog:
https://blogs.sap.com/2013/07/04/abap-news-for-release-740-abap-and-json/
Comments on the blog page contain more info.
Does Redshift support JSON fields, like Postgresql's json data type? If so what do I do to use it?
You can store JSON in Amazon Redshift, within a normal text field.
There are functions available to extract data from JSON fields, but it is not an effective way to store data since it doesn't leverage the full capabilities of Redshift's column-based architecture.
See: Amazon Redshift documentation - JSON Functions
UPDATE:
Redshift now supports Data column of type "super" which allows saving JSONs and also querying over it.
Added a link to video that further explains the new option:
https://www.youtube.com/watch?v=PR15TVZDgy4
I'm writing an API in Express, using Mongoose as my data layer. I'd like the API to be as self-describing as possible so my frontend can automatically generate forms and validation based on schema rules set up in my Mongoose models.
Is there any existing way to get a JSON representation of a Mongoose schema, or will I have to write my own? There seem to be plenty of JSON-to-Mongoose schema generators, but very little in the way of describing an existing schema.
I probably don't get a point. You can define your schema as Object and then use JSON.stringify on it. Or if you want, you can access all schema paths through model as Model.schema.paths.
I have a use case where I need to validate JSON objects against a schema that can change real time..
Let me explain my requirements..
I persist JSON objects (MongoDB).
Before persisting I MUST validate the data type of some of the
fields of JSON objects (mentioned in #1) against a schema.
I persist the schema in mongodb.
I always validate the JSON objects against the latest schema available in db. (so I dont think it matters much even if the schema can change in real time for me it is kinda static).
I am using a J2EE stack (Spring Framework).
Can anyone guide me here..?
Another way of doing it is to use an external library https://github.com/fge/json-schema-validator to do the work for you. The one I proposed supports draft 4 of JSON Schema.
The IBM DataPower appliance has JSON Schema validation support. This will allow you to offload validation to an appliance that is designed for it along with routing of data within te enterprise.