Add Hibernate 7 batches 2-6, batch 7, and batch 8: mapping styles, JPA annotations, natural IDs, @Immutable, stored procedures, in-memory test databases, JNDI mocking, proxies, associations, temporal mapping, named queries, HQL, Criteria API, EntityManager bootstrapping, Ehcache 3 L2 cache configuration, HikariCP connection pooling, Hibernate Validator CDI integration, aggregate functions, sorting, pagination, interceptors, and Hibernate Search 8 (Hibernate 7.4.5.Final + Spring Boot 4.1.1 + JDK 25)

src/main/java/com/ankurm/hibernatedemo/naturalid/ImmutableNaturalIdEntity.java

@@ -0,0 +1,44 @@
+package com.ankurm.hibernatedemo.naturalid;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import org.hibernate.annotations.NaturalId;
+
+/**
+ * {@code @NaturalId} with NO {@code mutable} attribute -- defaults to {@code mutable = false}
+ * (immutable). Deliberately does NOT add {@code @Column(updatable = false)}, so if Hibernate
+ * lets an UPDATE through at the SQL level, that is Hibernate's own natural-id immutability
+ * enforcement failing to stop it, not a JPA column-level guard doing the stopping.
+ *
+ * <p>Docs: docs/06-natural-ids.md, Topic 3.
+ */
+@Entity
+public class ImmutableNaturalIdEntity {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @NaturalId // mutable defaults to false
+    private String code;
+
+    public ImmutableNaturalIdEntity() {
+    }
+
+    public ImmutableNaturalIdEntity(String code) {
+        this.code = code;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getCode() {
+        return code;
+    }
+
+    public void setCode(String code) {
+        this.code = code;
+    }
+}