Skinz3 / Flex

Flex is a lightweight object-relational mapping (ORM) product for the Microsoft .NET Core and SQL : it provides a framework for mapping an object-oriented domain model to a traditional SQL database.

Flex

Flex is a lightweight object-relational mapping (ORM) product for the Microsoft .NET Core and SQL : it provides a framework for mapping an object-oriented domain model to a traditional SQL database. Written in C# .NET Core 6 using active record pattern. Flex currently supports MySQL and SQLite (Postgre soon)

Flex uses precompiled lambdas expressions for resource intensive reflexive tasks. Like entity instantiation or access to the property of the entity

Schema Mapping

  [Table("Users")]
  public class User : IEntity 
  { 
      [Primary(GenerationType.AutoIncrement)] 
      public int Id
      {
          get;
          set;
      }

      public string Name
      {
          get;
          set;
      }

      [Update]
      public string Ip
      {
          get;
          set;
      }

      [Blob] // <--- Fast serialization using Google Protobuf 
      public Certificate Certificate 
      {
          get;
          set;
      }

      [Transient]  // <--- This property is ignored in SQL Schema 
      public bool Connected
      {
          get;
          set;
      }
  }

• Mapping attributes

Name	Description	Status
Blob	Indicates that the field must be serialized in binary (anything that is not a primitive type and a collection)	✅
Foreign	Indicates that the concerned object is a foreign key of another table	❌
NotNull	Indicates that the property cannot have the value DbNull	✅
Primary	Indicates that the property is a primary key. It is also possible to provide an auto-increment parameter as an attribute parameter.	✅
Transient	Indicates that the property will be ignored by the mapping	✅

Interopability

  Database database = new Database(new MySqlProvider("myDb","localhost","root",""));
  // or
  Database database =  new Database(new SQLiteProvider("file.sqlite"));

Reading database

• Flex allows the creation of dynamic queries using System.Linq.

  Table<User> table = database.GetTable<User>();

  long count = table.Count();

  IEnumerable<User> Users = table.Select();

  IEnumerable<User> users = table.Select(x=> x.Username == "John Doe").GroupBy(x => x.Ip); // <--- Dynamic query builder

Writting database

  User user = new User();
  user.Name = "John Doe";
  user.Certificate = new Certificate();

  table.Insert(user);

  user.Ip = "127.0.0.1";

  table.Update(user);

  table.DeleteAll();

  database.Drop<User>();

Query Scheduler

• Schedulers can be used to reduce the number of transactions made to the database. Schedulers are thread safe. It is also possible to perform cyclic synchronization.

table.Scheduler.InsertLater(new User() { Name : "John" });
table.Scheduler.InsertLater(new User() { Name : "Ethan" });
table.Scheduler.InsertLater(new User() { Name : "William" });

table.Scheduler.Apply(); // <--- Only one query is executed.

Database Copy (from one SGBD to another)

  Database mySqlDb = new MySqlDatabase("MyDatabase","localhost","root","");
  Database sqlLiteDb = new SQLiteDatabase("database.sqlite");

  sqlLiteDb.CopyTo(mySqlDb);

Package Dependencies

Name	Version
MySql.Data	8.0.26
protobuf-net	3.0.101
System.Data.SQLite	1.0.115