Fix to #29297 - Seeding issue with JSON columns in EF Core 7 (#32015)

Adding validation step when using HasData with entities mapped to JSON, as well as normal entities navigating into JSON.

Fixes #29297

src/EFCore.Relational/Infrastructure/RelationalModelValidator.cs

@@ -2469,6 +2469,29 @@ protected virtual void ValidateIndexProperties(
         }
     }
 
+
+    /// <inheritdoc/>
+    protected override void ValidateData(IModel model, IDiagnosticsLogger<DbLoggerCategory.Model.Validation> logger)
+    {
+        foreach (var entityType in model.GetEntityTypes())
+        {
+            if (entityType.IsMappedToJson() && entityType.GetSeedData().Any())
+            {
+                throw new InvalidOperationException(RelationalStrings.HasDataNotSupportedForEntitiesMappedToJson(entityType.DisplayName()));
+            }
+
+            foreach (var navigation in entityType.GetNavigations().Where(x => x.ForeignKey.IsOwnership && x.TargetEntityType.IsMappedToJson()))
+            {
+                if (entityType.GetSeedData().Any(x => x.TryGetValue(navigation.Name, out var _)))
+                {
+                    throw new InvalidOperationException(RelationalStrings.HasDataNotSupportedForEntitiesMappedToJson(entityType.DisplayName()));
+                }
+            }
+        }
+
+        base.ValidateData(model, logger);
+    }
+
     /// <summary>
     ///     Validates that the triggers are unambiguously mapped to exactly one table.
     /// </summary>

src/EFCore.Relational/Properties/RelationalStrings.resx

@@ -427,6 +427,9 @@
   <data name="FunctionOverrideMismatch" xml:space="preserve">
     <value>The property '{propertySpecification}' has specific configuration for the function '{function}', but it isn't mapped to a column on that function return. Remove the specific configuration, or map an entity type that contains this property to '{function}'.</value>
   </data>
+  <data name="HasDataNotSupportedForEntitiesMappedToJson" xml:space="preserve">
+    <value>Can't use HasData for entity type '{entity}'. HasData is not supported for entities mapped to JSON.</value>
+  </data>
   <data name="IncompatibleTableCommentMismatch" xml:space="preserve">
     <value>Cannot use table '{table}' for entity type '{entityType}' since it is being used for entity type '{otherEntityType}' and the comment '{comment}' does not match the comment '{otherComment}'.</value>
   </data>

test/EFCore.Relational.Tests/Infrastructure/RelationalModelValidatorTest.Json.cs

@@ -565,6 +565,55 @@ public void Json_entity_mapped_to_a_table_but_its_parent_is_mapped_to_a_view()
             modelBuilder);
     }
 
+    [ConditionalFact]
+    public void SeedData_on_json_entity_throws_meaningful_exception()
+    {
+        var modelBuilder = CreateConventionModelBuilder();
+        modelBuilder.Entity<ValidatorJsonEntityBasic>(
+            b =>
+            {
+                b.HasData(new { Id = 1, OwnedReference = new { Name = "foo", Number = 1 } });
+                b.OwnsOne(
+                    x => x.OwnedReference, bb =>
+                    {
+                        bb.ToJson();
+                        bb.Ignore(x => x.NestedCollection);
+                        bb.Ignore(x => x.NestedReference);
+                    });
+                b.Ignore(x => x.OwnedCollection);
+            });
+
+        VerifyError(
+            RelationalStrings.HasDataNotSupportedForEntitiesMappedToJson(nameof(ValidatorJsonEntityBasic)),
+            modelBuilder);
+    }
+
+    [ConditionalFact]
+    public void SeedData_on_entity_with_json_navigation_throws_meaningful_exception()
+    {
+        var modelBuilder = CreateConventionModelBuilder();
+        modelBuilder.Entity<ValidatorJsonEntityBasic>(
+            b =>
+            {
+                b.HasData(new { Id = 1 });
+                b.OwnsMany(
+                    x => x.OwnedCollection, bb =>
+                    {
+                        bb.ToJson();
+                        bb.HasData(
+                            new { Name = "foo", Number = 1 },
+                            new { Name = "bar", Number = 2 });
+                        bb.Ignore(x => x.NestedCollection);
+                        bb.Ignore(x => x.NestedReference);
+                    });
+                b.Ignore(x => x.OwnedReference);
+            });
+
+        VerifyError(
+            RelationalStrings.HasDataNotSupportedForEntitiesMappedToJson(nameof(ValidatorJsonOwnedRoot)),
+            modelBuilder);
+    }
+
     private class ValidatorJsonEntityBasic
     {
         public int Id { get; set; }