Entity Framework Core

Entity Framework Core

Trigger On

• working on DbContext, migrations, model configuration, or EF queries
• reviewing tracking, loading, performance, or transaction behavior
• porting data access from EF6 or custom repositories to EF Core
• optimizing slow database queries

Documentation

• EF Core Overview
• Performance
• Efficient Querying
• Migrations
• What's New in EF Core 9

References

• patterns.md - Query patterns, tracking strategies, loading strategies, projections, compiled queries, pagination, and temporal tables
• anti-patterns.md - Common EF Core mistakes including N+1 queries, large contexts, generic repositories, and missing indexes

Workflow

1. Prefer EF Core for new development unless a documented gap requires Dapper or raw SQL
2. Keep DbContext lifetime scoped — align with unit of work
3. Review query translation — check generated SQL, avoid N+1
4. Treat migrations as first-class — reviewable, not throwaway
5. Be deliberate about provider behavior — cross-provider but not identical
6. Validate with query inspection — not just in-memory mental model

Current Upstream Notes

• EF Core v10.0.11 is a servicing release. It fixes Azure SQL compatibility-level 170 JSON translation so nested OPENJSON projections retain AS JSON, and keeps EF compatible with .NET 11 MemoryExtensions.Min/Max overload additions. Re-run provider-backed JSON queries and compile against the repository's selected target framework after upgrading.
• The August 2026 EF Core vs EF6 comparison remains the first stop for migration decisions. EF Core is the active cross-platform stack, but EF6-only EDMX/ObjectContext-heavy code should not move without a feature inventory and database-backed equivalence tests.

DbContext Patterns

Basic Configuration