Query: Change JSONQuery.Path to be list of PathSegment

Resolves #28838
Resolves #28836

src/EFCore.Relational/Query/EntityProjectionExpression.cs

@@ -22,7 +22,7 @@ public class EntityProjectionExpression : Expression
  /// <summary>
  /// Creates a new instance of the <see cref="EntityProjectionExpression" /> class.
  /// </summary>
- /// <param name="entityType">The entity type to shape.</param>
+ /// <param name="entityType">An entity type to shape.</param>
  /// <param name="propertyExpressionMap">A dictionary of column expressions corresponding to properties of the entity type.</param>
  /// <param name="discriminatorExpression">A <see cref="SqlExpression" /> to generate discriminator for each concrete entity type in hierarchy.</param>
  public EntityProjectionExpression(
@@ -115,26 +115,15 @@ public virtual EntityProjectionExpression MakeNullable()
  discriminatorExpression = ce.MakeNullable();
  }
 
- 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 newJsonQueryExpression = jsonQueryExpression.MakeNullable();
  var newShaper = shaper.Update(newJsonQueryExpression).MakeNullable();
  ownedNavigationMap[navigation] = newShaper;
  }
@@ -145,34 +134,6 @@ public virtual EntityProjectionExpression MakeNullable()
  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>