Start Debugging

Tag: ef-core

23 posts · Page 1 of 3

2026-05-31 ef-core ef-core-11 csharp

How to use ExecuteUpdate and ExecuteDelete for bulk writes in EF Core 11

A complete guide to ExecuteUpdate and ExecuteDelete in EF Core 11: the SQL they emit, the change-tracker gotcha that silently overwrites your bulk write, transactions, concurrency control with the affected-row count, and the EF Core 10 delegate setters that let you build conditional updates with plain if statements.

2026-05-26 ef-core dotnet-11 sql-server

EF Core 11 Preview 4: Temporal Table Period Columns Can Finally Be Real Properties

EF Core 11 Preview 4 drops the long-standing shadow-property restriction on SQL Server temporal tables. PeriodStart and PeriodEnd can now be regular CLR properties, configured with strongly-typed HasPeriodStart and HasPeriodEnd lambdas.

2026-05-23 comparison ef-core dapper

EF Core compiled queries vs raw SQL vs Dapper: which read path wins?

For read-heavy paths in .NET 11, plain EF Core with AsNoTracking is within ~5% of Dapper. Reach for compiled queries on a profiled single-row hot path, and Dapper only for the lowest latency or SQL LINQ can't express.

2026-05-21 comparison csharp linq

IEnumerable vs IAsyncEnumerable vs IQueryable in C#: which one should the method return?

Three sequence interfaces, three execution models. Use IQueryable when a database can translate the query, IAsyncEnumerable when the producer is async and you want to stream, IEnumerable for everything else in memory.

2026-05-20 comparison ef-core dapper

EF Core 11 vs Dapper for bulk inserts: real benchmark

For bulk inserts in .NET 11, neither EF Core nor Dapper wins. SqlBulkCopy does. This is the benchmark, the why, and the seat each tool deserves.

2026-05-14 errors csharp dotnet

Fix: A possible object cycle was detected

System.Text.Json refuses to serialize graphs with back-references. Set ReferenceHandler.IgnoreCycles, project to a DTO, or mark the back-pointer with [JsonIgnore]. Preserve is a last resort.

2026-05-14 errors csharp dotnet

Fix: SqlException: Timeout expired during EF Core migrations

Migrations use the design-time DbContext, not your runtime CommandTimeout. Set the timeout via UseSqlServer(o => o.CommandTimeout(...)), the connection string Command Timeout, or Database.SetCommandTimeout before Migrate().

2026-05-11 errors csharp dotnet

Fix: dotnet ef migrations add fails with 'Unable to create an object of type DbContext'

EF Core's design-time tools could not instantiate your DbContext. Either expose a host via WebApplication.CreateBuilder, point to the right startup project, or implement IDesignTimeDbContextFactory.

2026-05-07 errors csharp dotnet

Fix: The instance of entity type cannot be tracked because another instance with the same key value is already being tracked

EF Core 11 throws when two objects share a primary key inside one DbContext. Detach the old one or update it in place. AsNoTracking on the read prevents the collision.

2026-05-07 errors csharp dotnet

Fix: A second operation was started on this context instance before a previous operation completed

EF Core throws when two awaits run in parallel on the same DbContext. Await each call sequentially, or get a new DbContext per concurrent unit of work via IDbContextFactory.