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Tag: ef-core

89 posts · Page 4 of 9

2026-08-30 errors ef-core ef-core-11

Fix: CREATE DATABASE permission denied in database 'master' when running dotnet ef database update

EF Core's Migrate() always checks whether the database exists and creates it if not, from a hardcoded master connection. Grant CREATE ANY DATABASE, fix the login's access to the existing database, or ship an idempotent SQL script instead.

2026-08-30 errors ef-core maui

Fix: Model building is not supported when publishing with NativeAOT in a .NET MAUI iOS build

iOS builds set DynamicCodeSupport=false, so EF Core refuses to build the model even though you never enabled NativeAOT. Ship a compiled model plus precompiled queries, or turn the interpreter back on.

2026-08-23 ef-core linq csharp

How to write reusable LINQ predicates that EF Core can translate in Where, Select, and OrderBy

A bool helper method throws "could not be translated". An Expression<Func<T, bool>> does not. Here is how to compose, nest, and reuse expression trees in EF Core 11 without LINQKit, with the real SQL for every case.

2026-08-19 errors ef-core dotnet

Fix: "An exception was thrown while attempting to evaluate a LINQ query parameter expression" in EF Core 11

EF Core throws this when a client-evaluated piece of your query throws while EF evaluates it. Read InnerException, turn on EnableSensitiveDataLogging, and move the null check outside the lambda.

2026-08-17 ef-core ef-core-11 sql-server

How to generate a primary key from a database sequence on insert in EF Core 11

Move a key off IDENTITY and onto a SQL Server sequence in EF Core 11 with UseSequence: the exact SQL EF emits, why explicit key values suddenly work without IDENTITY_INSERT, the bigint sequence feeding an int column, and the gaps you have to design around.

2026-08-16 csharp dotnet dotnet-11

How to use IDbContextFactory<T> from a singleton service in Blazor

A singleton cannot inject a DbContext, but it can inject IDbContextFactory<T>, because AddDbContextFactory registers the factory as a singleton by default. Create and dispose one context per call, never cache the instance.

2026-08-12 errors dotnet dotnet-10

Fix: dotnet tool install --global dotnet-ef throws an error

Every way dotnet tool install --global dotnet-ef fails on the .NET 10 SDK, with the exact message and exit code for each: already installed, version not found, downgrade blocked, shim conflict, dead NuGet feed, and the runtime mismatch that only breaks after the install succeeds.

2026-08-10 ef-core ef-core-11 sql-server

How to call a stored procedure and map its results in EF Core 11

Use FromSql on a DbSet when the procedure returns full entity rows, Database.SqlQuery<T> when it returns a projection, and ExecuteSql when it returns nothing. Never chain a LINQ operator onto an EXEC, and never read an output parameter before the reader is disposed.

2026-08-09 ef-core ef-core-11 migrations

How to rename a table in an EF Core 11 migration without losing data

EF Core scaffolds RenameTable when you change the table name, but DropTable plus CreateTable when you rename the entity class. Here is how to tell the two apart, the ToTable trick that makes a class rename free, and the column-rename bug that silently swaps your data.

2026-08-07 comparison dotnet aspnetcore

WebApplicationFactory vs Testcontainers for ASP.NET Core integration tests

They are not alternatives. WebApplicationFactory boots your app, Testcontainers boots your dependencies. Measured on .NET SDK 10.0.201: a container fixture costs 1.7 s per class against 10 ms for SQLite, and a HasMaxLength(16) violation that Postgres rejects with 22001 is silently accepted by SQLite.