Can you share your experience working with different types of databases, their features, and applications?

In my practice, I have worked with both relational and non-relational databases, each with its own features and areas of application.

Relational databases (SQL), such as Microsoft SQL Server, PostgreSQL, MySQL, are well-suited for structured data with clear relationships. They support transactions, complex queries, and ensure data integrity. They are used in systems with a clear data schema, such as banking applications, ERP.

Non-relational databases (NoSQL) are divided into several types:

• Document-oriented (MongoDB, CouchDB) — store data in JSON-like documents, flexible in structure, convenient for rapidly changing data.
• Key-value (Redis, Riak) — very fast, suitable for caching and session storage.
• Graph (Neo4j) — optimal for storing and analyzing relationships, such as in social networks.

In C#, I often use Entity Framework for working with relational databases, which simplifies data handling through ORM. For NoSQL, I used drivers for MongoDB or Redis.

Example of connecting to MongoDB in C#:

var client = new MongoClient("mongodb://localhost:27017");
var database = client.GetDatabase("mydb");
var collection = database.GetCollection<BsonDocument>("mycollection");

The choice of database depends on the project requirements: if strict structure and transactions are needed — SQL, if flexibility and scalability — NoSQL.