BookRepository: embedded-path queries + record projection (with the nested-path projection corner case)

src/main/java/com/ankurm/sdjpa4demo/repo/BookRepository.java

@@ -1,16 +1,29 @@
 package com.ankurm.sdjpa4demo.repo;
 
 import com.ankurm.sdjpa4demo.domain.Book;
+import com.ankurm.sdjpa4demo.domain.BookSummary;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import java.math.BigDecimal;
 import java.util.List;
 
 public interface BookRepository extends JpaRepository<Book, Long> {
 
-    List<Book> findByPriceGreaterThanEqual(BigDecimal price);
+    // Embedded-value-object path traversal: price -> amount. Resolves to: where b.price.amount >= :min
+    List<Book> findByPriceAmountGreaterThanEqual(BigDecimal min);
 
-    // Single-result derived query that can match MORE than one row on bad data:
+    // Single-result derived query over an embedded path that can match MORE than one row on bad data:
     // demonstrates IncorrectResultSizeDataAccessException (the "non-unique" edge case).
-    Book findByPrice(BigDecimal price);
+    Book findByPriceAmount(BigDecimal price);
+
+    // CORNER CASE: a derived-query class-based (record) projection matches constructor-parameter names
+    // against DIRECT entity properties only. BookSummary's "amount" component does not resolve against
+    // the nested b.price.amount path this way - PropertyReferenceException: No property 'amount' found
+    // for type 'Book' (verified by actually running the derived-method form before falling back to this).
+    // A @Query constructor expression works for nested/embedded paths; the derived-method-only form does not.
+    @Query("select new com.ankurm.sdjpa4demo.domain.BookSummary(b.title, b.price.amount) "
+            + "from Book b where b.price.amount <= :max")
+    List<BookSummary> findByPriceAmountLessThanEqual(@Param("max") BigDecimal max);
 }