# Entity Framework

<span class="status stable">Stable</span>

Entity Framework (EF) is an open-source Object-Relational Mapper (ORM) framework for .NET.

| Property                | Value               |
| ----------------------- | ------------------- |
| **Current Version**     | EF Core 10.x        |
| **Forge Compatibility** | Forge 3.0 (.NET 10) |
| **Status**              | Stable              |

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## Description

Entity Framework (EF) is an open-source Object-Relational Mapper (ORM) framework for .NET, developed by Microsoft. It enables developers to interact with databases using .NET objects, eliminating the need to write most of the data-access code typically required in applications.

EF Core supports multiple database providers including SQL Server, Oracle, Cosmos DB, and PostgreSQL.

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## Why we use it

Entity Framework is used to map database objects to C# objects, which makes it easier to create database interactions. We currently use it for:

- **Oracle databases** - Database-first approach for legacy data
- **Cosmos DB** - Code-first approach for new applications
- **SQL Server** - Both code-first and database-first approaches

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## When to use it

- ✅ Data access layer for relational databases
- ✅ Cosmos DB integration via the Cosmos DB provider
- ✅ Database migrations and schema management

**When to consider alternatives:**

- ⚠️ Extreme Latency Sensitivity: Scenarios requiring sub-millisecond optimization where even the minimal overhead of object tracking/mapping is too costly.
- ⚠️ Complex Reporting/Analytics: Queries involving hundreds of lines of SQL, CTEs, or window functions where LINQ generation might be unpredictable or harder to optimize than hand-written SQL.
- ⚠️ Massive Bulk Operations: While `ExecuteUpdate` handles many cases, inserting millions of rows may still be faster with raw SQL `SqlBulkCopy` or specialized bulk libraries.

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## Prerequisites

- .NET 10 SDK
- Database connection (Oracle, Cosmos DB, SQL Server, etc.)
- EF Core CLI tool (optional, for migrations)

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## Related Documentation

| Guide                                                               | Description                  |
| ------------------------------------------------------------------- | ---------------------------- |
| [Cosmos DB NoSQL](../../guides/development/data/cosmos-nosql.md)    | Using EF Core with Cosmos DB |
| [Oracle Database](../../guides/development/data/database-oracle.md) | Using EF Core with Oracle    |

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## Links

- [Entity Framework Core Documentation](https://learn.microsoft.com/en-us/ef/core/)
- [Install EF CLI Tools](https://learn.microsoft.com/en-us/ef/core/get-started/overview/install#get-the-net-core-cli-tools)