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Tag: efcore

14 posts · Page 1 of 2

2026-10-06 errors efcore ef-core-11

Fix: Invalid column name 'Value' when using SqlQueryRaw<T> for a scalar result in EF Core

EF Core wraps a scalar SqlQuery<T> in a subquery and selects a column named Value as soon as you add First, Where, Max or Single. Alias your SQL column AS Value, or materialize first.

2026-09-29 errors efcore dotnet

Fix: EF Core `Contains` on a static readonly `IList<T>` or `ISet<T>` could not be translated

EF Core 8, 9 and 10 fail to translate Contains when the list is a static readonly field typed as IList, ICollection, ISet or IReadOnlySet. Call Enumerable.Contains explicitly, or upgrade to EF Core 11.

2026-09-19 migration efcore efcore-11

Migrate an EF Core Cosmos app after the generated id escaping change in EF Core 11

EF Core 11 stops escaping '/', '\', '?' and '#' in generated Cosmos DB id values, so documents written by EF Core 8-10 stop resolving by key. How to find out if you are affected, when to set the EscapeIllegalCosmosIdCharacters switch, and how to rewrite the ids safely with a transactional batch.

2026-09-14 errors efcore dotnet

Fix: InvalidOperationException: Nullable object must have a value in an EF Core 11 projection

EF Core throws this when a Select reads a SQL NULL into a non-nullable int, decimal or DateTime. Cast the member to its nullable type and add ?? default, or guard the navigation with a null check.

2026-07-08 migration efcore 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 efcore 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 efcore 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 efcore 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 efcore 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 efcore 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.