Json Columns query work

src/EFCore.Relational/Extensions/RelationalEntityTypeExtensions.cs

@@ -1758,10 +1758,10 @@ public static void SetJsonPropertyName(this IMutableEntityType entityType, strin
  Check.NullButNotEmpty(name, nameof(name)));
 
  /// <summary>
- /// Gets the <see cref="ConfigurationSource" /> for the JSON property name for a given entity Type.
+ /// Gets the <see cref="ConfigurationSource" /> for the JSON property name for a given entity type.
  /// </summary>
  /// <param name="entityType">The entity type.</param>
- /// <returns>The <see cref="ConfigurationSource" /> for the JSON property name for a given navigation.</returns>
+ /// <returns>The <see cref="ConfigurationSource" /> for the JSON property name for a given entity type.</returns>
  public static ConfigurationSource? GetJsonPropertyNameConfigurationSource(this IConventionEntityType entityType)
  => entityType.FindAnnotation(RelationalAnnotationNames.JsonPropertyName)?.GetConfigurationSource();
 

src/EFCore.Relational/Metadata/Internal/RelationalKeyExtensions.cs

@@ -124,6 +124,11 @@ public static bool AreCompatible(
  return null;
  }
 
+ if (key.DeclaringEntityType.IsMappedToJson())
+ {
+ return null;
+ }
+
  string? name;
  if (key.IsPrimaryKey())
  {

src/EFCore.Relational/Metadata/Internal/RelationalModel.cs

@@ -468,7 +468,7 @@ private static void CreateTableMapping(
  var jsonColumnTypeMapping = relationalTypeMappingSource.FindMapping(typeof(JsonElement))!;
  var jsonColumn = new JsonColumn(containerColumnName, jsonColumnTypeMapping.StoreType, table, jsonColumnTypeMapping.ProviderValueComparer);
  table.Columns.Add(containerColumnName, jsonColumn);
- jsonColumn.IsNullable = !ownership.IsRequired || !ownership.IsUnique;
+ jsonColumn.IsNullable = !ownership.IsRequiredDependent || !ownership.IsUnique;
 
  if (ownership.PrincipalEntityType.BaseType != null)
  {

src/EFCore.Relational/Properties/RelationalStrings.resx

@@ -481,6 +481,9 @@
  <data name="InvalidPropertyInSetProperty" xml:space="preserve">
  <value>The following lambda argument to 'SetProperty' does not represent a valid property to be set: '{propertyExpression}'.</value>
  </data>
+ <data name="JsonCantNavigateToParentEntity" xml:space="preserve">
+ <value>Can't navigate from JSON-mapped entity '{jsonEntity}' to its parent entity '{parentEntity}' using navigation '{navigation}'. Entities mapped to JSON can only navigate to their children.</value>
+ </data>
  <data name="JsonEntityMappedToDifferentViewThanOwner" xml:space="preserve">
  <value>Entity '{jsonType}' is mapped to JSON and also to a view '{viewName}', but its owner '{ownerType}' is mapped to a different view '{ownerViewName}'. Every entity mapped to JSON must also map to the same view as its owner.</value>
  </data>
@@ -517,9 +520,18 @@
  <data name="JsonEntityWithTableSplittingIsNotSupported" xml:space="preserve">
  <value>Table splitting is not supported for entities containing entities mapped to JSON.</value>
  </data>
+ <data name="JsonErrorExtractingJsonProperty" xml:space="preserve">
+ <value>An error occurred while reading a JSON value for property '{entityType}.{propertyName}'. See the inner exception for more information.</value>
+ </data>
+ <data name="JsonNodeMustBeHandledByProviderSpecificVisitor" xml:space="preserve">
+ <value>This node should be handled by provider-specific sql generator.</value>
+ </data>
  <data name="JsonPropertyNameShouldBeConfiguredOnNestedNavigation" xml:space="preserve">
  <value>The JSON property name should only be configured on nested owned navigations.</value>
  </data>
+ <data name="JsonRequiredEntityWithNullJson" xml:space="preserve">
+ <value>Entity {entity} is required but the JSON element containing it is null.</value>
+ </data>
  <data name="KeylessMappingStrategy" xml:space="preserve">
  <value>The mapping strategy '{mappingStrategy}' used for '{entityType}' is not supported for keyless entity types. See https://go.microsoft.com/fwlink/?linkid=2130430 for more information.</value>
  </data>

src/EFCore.Relational/Query/EntityProjectionExpression.cs

@@ -17,7 +17,7 @@ namespace Microsoft.EntityFrameworkCore.Query;
 public class EntityProjectionExpression : Expression
 {
  private readonly IReadOnlyDictionary<IProperty, ColumnExpression> _propertyExpressionMap;
- private readonly Dictionary<INavigation, EntityShaperExpression> _ownedNavigationMap = new();
+ private readonly Dictionary<INavigation, EntityShaperExpression> _ownedNavigationMap;
 
  /// <summary>
  /// Creates a new instance of the <see cref="EntityProjectionExpression" /> class.
@@ -29,9 +29,23 @@ public EntityProjectionExpression(
  IEntityType entityType,
  IReadOnlyDictionary<IProperty, ColumnExpression> propertyExpressionMap,
  SqlExpression? discriminatorExpression = null)
+ : this(
+ entityType,
+ propertyExpressionMap,
+ new Dictionary<INavigation, EntityShaperExpression>(),
+ discriminatorExpression)
+ {
+ }
+
+ private EntityProjectionExpression(
+ IEntityType entityType,
+ IReadOnlyDictionary<IProperty, ColumnExpression> propertyExpressionMap,
+ Dictionary<INavigation, EntityShaperExpression> ownedNavigationMap,
+ SqlExpression? discriminatorExpression = null)
  {
  EntityType = entityType;
  _propertyExpressionMap = propertyExpressionMap;
+ _ownedNavigationMap = ownedNavigationMap;
  DiscriminatorExpression = discriminatorExpression;
  }
 
@@ -69,8 +83,16 @@ protected override Expression VisitChildren(ExpressionVisitor visitor)
  var discriminatorExpression = (SqlExpression?)visitor.Visit(DiscriminatorExpression);
  changed |= discriminatorExpression != DiscriminatorExpression;
 
+ var ownedNavigationMap = new Dictionary<INavigation, EntityShaperExpression>();
+ foreach (var (navigation, entityShaperExpression) in _ownedNavigationMap)
+ {
+ var newExpression = (EntityShaperExpression)visitor.Visit(entityShaperExpression);
+ changed |= newExpression != entityShaperExpression;
+ ownedNavigationMap[navigation] = newExpression;
+ }
+
  return changed
- ? new EntityProjectionExpression(EntityType, propertyExpressionMap, discriminatorExpression)
+ ? new EntityProjectionExpression(EntityType, propertyExpressionMap, ownedNavigationMap, discriminatorExpression)
  : this;
  }
 
@@ -92,7 +114,65 @@ public virtual EntityProjectionExpression MakeNullable()
  // if discriminator is column then we need to make it nullable
  discriminatorExpression = ce.MakeNullable();
  }
- return new EntityProjectionExpression(EntityType, propertyExpressionMap, discriminatorExpression);
+
+ var primaryKeyProperties = GetMappedKeyProperties(EntityType.FindPrimaryKey()!);
+ var ownedNavigationMap = new Dictionary<INavigation, EntityShaperExpression>();
+ foreach (var (navigation, shaper) in _ownedNavigationMap)
+ {
+ if (shaper.EntityType.IsMappedToJson())
+ {
+ // even if shaper is nullable, we need to make sure key property map contains nullable keys,
+ // if json entity itself is optional, the shaper would be null, but the PK of the owner entity would be non-nullable intially
+ Debug.Assert(primaryKeyProperties != null, "Json entity type can't be keyless");
+
+ var jsonQueryExpression = (JsonQueryExpression)shaper.ValueBufferExpression;
+ var ownedPrimaryKeyProperties = GetMappedKeyProperties(shaper.EntityType.FindPrimaryKey()!)!;
+ var nullableKeyPropertyMap = new Dictionary<IProperty, ColumnExpression>();
+ for (var i = 0; i < primaryKeyProperties.Count; i++)
+ {
+ nullableKeyPropertyMap[ownedPrimaryKeyProperties[i]] = propertyExpressionMap[primaryKeyProperties[i]];
+ }
+
+ // reuse key columns from owner (that we just made nullable), so that the references are the same
+ var newJsonQueryExpression = jsonQueryExpression.MakeNullable(nullableKeyPropertyMap);
+ var newShaper = shaper.Update(newJsonQueryExpression).MakeNullable();
+ ownedNavigationMap[navigation] = newShaper;
+ }
+ }
+
+ return new EntityProjectionExpression(
+ EntityType,
+ propertyExpressionMap,
+ ownedNavigationMap,
+ discriminatorExpression);
+
+ static IReadOnlyList<IProperty>? GetMappedKeyProperties(IKey? key)
+ {
+ if (key == null)
+ {
+ return null;
+ }
+
+ if (!key.DeclaringEntityType.IsMappedToJson())
+ {
+ return key.Properties;
+ }
+
+ // TODO: fix this once we enable json entity being owned by another owned non-json entity (issue #28441)
+
+ // for json collections we need to filter out the ordinal key as it's not mapped to any column
+ // there could be multiple of these in deeply nested structures,
+ // so we traverse to the outermost owner to see how many mapped keys there are
+ var currentEntity = key.DeclaringEntityType;
+ while (currentEntity.IsMappedToJson())
+ {
+ currentEntity = currentEntity.FindOwnership()!.PrincipalEntityType;
+ }
+
+ var count = currentEntity.FindPrimaryKey()!.Properties.Count;
+
+ return key.Properties.Take(count).ToList();
+ }
  }
 
  /// <summary>
@@ -119,6 +199,16 @@ public virtual EntityProjectionExpression UpdateEntityType(IEntityType derivedTy
  }
  }
 
+ var ownedNavigationMap = new Dictionary<INavigation, EntityShaperExpression>();
+ foreach (var (navigation, entityShaperExpression) in _ownedNavigationMap)
+ {
+ if (derivedType.IsAssignableFrom(navigation.DeclaringEntityType)
+ || navigation.DeclaringEntityType.IsAssignableFrom(derivedType))
+ {
+ ownedNavigationMap[navigation] = entityShaperExpression;
+ }
+ }
+
  var discriminatorExpression = DiscriminatorExpression;
  if (DiscriminatorExpression is CaseExpression caseExpression)
  {
@@ -130,7 +220,7 @@ public virtual EntityProjectionExpression UpdateEntityType(IEntityType derivedTy
  discriminatorExpression = caseExpression.Update(operand: null, whenClauses, elseResult: null);
  }
 
- return new EntityProjectionExpression(derivedType, propertyExpressionMap, discriminatorExpression);
+ return new EntityProjectionExpression(derivedType, propertyExpressionMap, ownedNavigationMap, discriminatorExpression);
  }
 
  /// <summary>