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/test/java/com/ankurm/hibernatedemo/persistenceannotations/JsonColumnOnH2Test.java

@@ -0,0 +1,51 @@
+package com.ankurm.hibernatedemo.persistenceannotations;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import com.ankurm.hibernatedemo.HibernateDemoApplication;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+/**
+ * Does {@code @JdbcTypeCode(SqlTypes.JSON)} actually work against H2 2.4.240? Honest empirical
+ * check -- if H2 rejects it, this test says so instead of asserting success.
+ *
+ * <p>Docs: docs/05-jpa-persistence-annotations.md, Topic 2.
+ */
+@SpringBootTest(classes = HibernateDemoApplication.class)
+class JsonColumnOnH2Test {
+
+    @Autowired
+    private EntityManagerFactory emf;
+
+    @Test
+    void jdbcTypeCodeJson_onH2_roundTripsAMap() {
+        EntityManager em = emf.createEntityManager();
+        em.getTransaction().begin();
+        JsonColumnEntity e = new JsonColumnEntity(Map.of("color", "red", "qty", 5));
+        em.persist(e);
+        em.getTransaction().commit();
+        Long id = e.getId();
+        em.close();
+
+        EntityManager em2 = emf.createEntityManager();
+        JsonColumnEntity loaded = em2.find(JsonColumnEntity.class, id);
+        em2.close();
+
+        System.out.println("RESULT[jdbctypecode-json-h2]: persisted+loaded details=" + loaded.getDetails());
+        assertThat(loaded.getDetails()).containsEntry("color", "red");
+
+        // Inspect the actual column type H2 chose for it.
+        EntityManager em3 = emf.createEntityManager();
+        Object colType = em3.createNativeQuery(
+                "select data_type from information_schema.columns "
+                        + "where table_name = 'JSON_COLUMN_ENTITY' and column_name = 'DETAILS'")
+                .getSingleResult();
+        em3.close();
+        System.out.println("RESULT[jdbctypecode-json-h2]: H2 column type for the JSON field = " + colType);
+    }
+}