dotnet/efcore · error · InvalidOperationException

The view '{view}' cannot be used for entity type '{entityTyp

Error message

The view '{view}' cannot be used for entity type '{entityType}' since it is being used for entity type '{otherEntityType}' and there is a relationship between their primary keys in which '{entityType}' is the dependent, but '{entityType}' has a base entity type mapped to a different view. Either map '{otherEntityType}' to a different view, or invert the relationship between '{entityType}' and '{otherEntityType}'.

What it means

The view-sharing analog of error 429. When entity types share a database view, a dependent linked by a PK foreign key must not itself have a base entity type mapped to a different view — the row cannot live in two views. The validator at line 1342-1353 throws IncompatibleViewDerivedRelationship when it finds a linking FK to another shared type while the current type has a base type elsewhere.

Source

Thrown at src/EFCore.Relational/Infrastructure/RelationalModelValidator.cs:1348

        foreach (var mappedType in mappedTypes)
        {
            if (mappedType.BaseType != null && unvalidatedTypes.Contains(mappedType.BaseType))
            {
                continue;
            }

            if (mappedType.FindPrimaryKey() != null
                && mappedType.FindForeignKeys(mappedType.FindPrimaryKey()!.Properties)
                    .Any(fk => fk.PrincipalKey.IsPrimaryKey()
                        && unvalidatedTypes.Contains(fk.PrincipalEntityType)))
            {
                if (mappedType.BaseType != null)
                {
                    var principalType = mappedType.FindForeignKeys(mappedType.FindPrimaryKey()!.Properties)
                        .First(fk => fk.PrincipalKey.IsPrimaryKey()
                            && unvalidatedTypes.Contains(fk.PrincipalEntityType))
                        .PrincipalEntityType;
                    throw new InvalidOperationException(
                        RelationalStrings.IncompatibleViewDerivedRelationship(
                            storeObject.DisplayName(),
                            mappedType.DisplayName(),
                            principalType.DisplayName()));
                }

                continue;
            }

            if (root != null)
            {
                throw new InvalidOperationException(
                    RelationalStrings.IncompatibleViewNoRelationship(
                        storeObject.DisplayName(),
                        mappedType.DisplayName(),
                        root.DisplayName()));
            }

View on GitHub (pinned to dbf9771522)

Solutions

1. Map the principal entity to a different view so the dependent's inheritance and view-sharing do not conflict.
2. Invert the relationship so the entity currently marked dependent becomes principal.
3. Unify the view mapping for the inheritance chain, or break the inheritance relationship for the shared type.

Example fix

// before: OrderViewDetail derives from BaseViewEntity mapped to 'BaseView'
//         and shares view 'OrderView' with Order
modelBuilder.Entity<Order>().ToView("OrderView");
modelBuilder.Entity<OrderViewDetail>().ToView("OrderView");
modelBuilder.Entity<BaseViewEntity>().ToView("BaseView");

// after: move Order to a distinct view
modelBuilder.Entity<Order>().ToView("OrderMain");
modelBuilder.Entity<OrderViewDetail>().ToView("OrderView");

foreach (var et in modelBuilder.Model.GetEntityTypes())
{
    var viewName = et.GetViewName();
    if (viewName == null || et.BaseType == null) continue;
    var baseView = et.BaseType.GetViewName();
    if (viewName == baseView) continue;

    var pk = et.FindPrimaryKey();
    if (pk == null) continue;
    var linkingFk = et.FindForeignKeys(pk.Properties)
        .FirstOrDefault(fk => fk.PrincipalKey.IsPrimaryKey()
            && fk.PrincipalEntityType.GetViewName() == viewName);
    if (linkingFk != null)
        throw new InvalidOperationException(
            $"{et.Name} maps view '{viewName}' with a linking FK but its base maps view '{baseView}'.");
}

When it happens

Trigger: Mapping an entity to a view (`.ToView("V")`) where that entity has both a base type on a different view and an identifying FK relationship to a principal on the shared view. Detected in ValidateSharedViewCompatibility.

Common situations: Using views for read models over an inheritance hierarchy where one branch was split to its own view; refactoring TPT-style view mapping; query-only entities that accidentally retain an inheritance link to a table-mapped base.

Related errors

• Both '{entityType}' and '{otherEntityType}' are mapped to th
• '{entityType}' is mapped to the view '{view}' while '{otherE
• Trigger '{trigger}' is defined on entity type '{entityType}'
• The entity type '{entityType}' is mapped to the 'DbFunction'
• Both entity type '{entityType1}' and '{entityType2}' were co

AI-assisted analysis of dotnet/efcore@dbf9771522 (2026-08-06). Data as JSON: /api/errors/6aaad067246ad567. Report an issue: GitHub.