abp/docs/en/Unit-Of-Work.md

Unit of Work

ABP Framework's Unit Of Work (UOW) implementation provides an abstraction and control on a database connection and transaction scope in an application.

Once a new UOW started, it creates an ambient scope that is participated by all the database operations performed in the current scope and considered as a single transaction boundary. The operations are committed (on success) or rolled back (on exception) all together.

ABP's UOW system is;

• Works conventional, so most of the times you don't deal with UOW at all.
• Database provider independent.
• Web independent, that means you can create unit of work scopes in any type of applications beside web applications/services.

Conventions

The following method types are considered as a unit of work:

• ASP.NET Core MVC Controller Actions.
• ASP.NET Core Razor Page Handlers.
• Application service methods.
• Repository methods.

A UOW automatically begins for these methods except if there is already a surrounding (ambient) UOW in action. Examples;

• If you call a repository method and there is no UOW started yet, it automatically begins a new transactional UOW that involves all the operations done in the repository method and commits the transaction if the repository method doesn't throw any exception. The repository method doesn't know about UOW or transaction at all. It just works on a regular database objects (DbContext for EF Core, for example) and the UOW is handled by the ABP Framework.
• If you call an application service method, the same UOW system works just as explained above. If the application service method uses some repositories, the repositories don't begin a new UOW, but participates to the current unit of work started by the ABP Framework for the application service method.
• The same is true for an ASP.NET Core controller action. If the operation has started with a controller action, then the UOW scope is the controller action's method body.

All of these are automatically handled by the ABP Framework. The rest of this document explains the UOW system in details and options provided to fine control the UOW system.