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EF Core

107 posts · Page 7 of 11

2026-07-08 migration ef-core dotnet

Migrate from HasData seeding to UseAsyncSeeding in EF Core 11

A step-by-step guide to moving seed data off HasData and onto UseSeeding and UseAsyncSeeding in EF Core 11, including the DeleteData migration trap that wipes your existing rows if you skip it.

2026-07-07 comparison ef-core dotnet

Named query filters vs a single global query filter in EF Core 11: which should you use?

Both produce the same SQL. Reach for named filters only when you need to disable one predicate independently; a single combined filter is simpler for one concern in EF Core 11.

2026-07-04 errors ef-core dotnet

Fix: "The LINQ expression could not be translated" in EF Core 11

EF Core 11 throws this when a Where or OrderBy calls a method it cannot turn into SQL. Rewrite the predicate into translatable operators, or pull the data client-side with AsEnumerable first.

2026-07-04 errors ef-core dotnet

Fix: "The required column 'X' was not present in the results of a 'FromSql' operation" in EF Core 11

EF Core throws this when your raw SQL does not return every column the entity maps to, or the column names do not match. Return all mapped columns with matching names, or query a scalar/keyless type instead.

2026-07-03 dotnet ef-core csharp

How to use named query filters for soft delete and multi-tenancy in EF Core 11

Apply two independent global query filters to the same entity in EF Core 11: a soft-delete filter and a tenant filter, each named so you can disable one without the other via IgnoreQueryFilters.

2026-06-30 comparison ef-core dotnet

HasData vs UseSeeding for seeding data in EF Core 11: which should you use?

Use HasData only for fixed, model-owned reference data. Use UseSeeding and UseAsyncSeeding for everything else in EF Core 11. A side-by-side comparison with the rules that force the decision.

2026-06-26 errors csharp dotnet

Fix: FOREIGN KEY constraint failed when deleting an entity in EF Core 11

EF Core throws FOREIGN KEY constraint failed because the parent still has dependents the database refuses to orphan. Load the children, make the relationship optional, or configure OnDelete.

2026-06-26 errors csharp dotnet

Fix: No service for type 'Microsoft.EntityFrameworkCore.DbContextOptions' has been registered

EF Core throws this when AddDbContext never ran, ran after Build, or your context's constructor takes the wrong DbContextOptions. Register before Build and use DbContextOptions<YourContext>.

2026-06-25 errors csharp dotnet

Fix: The seed entity for entity type 'X' cannot be added because a non-zero value is required for property 'Id'

HasData seeds an entity with a store-generated key but no explicit value. Give every seed row a stable non-zero Id, or switch to UseSeeding for generated keys.

2026-06-23 how-to ef-core ef-core-11

How to do keyset (cursor) pagination in EF Core 11

Replace Skip/Take with a WHERE clause that seeks past the last row you saw. Order by a fully unique key, carry the last row's values as a cursor, and EF Core 11 turns the next page into an index seek instead of an OFFSET scan.