update

src/main/java/dev/struchkov/example/hibernate/nbfe/problem/GeneratePost.java

@@ -0,0 +1,58 @@
+package dev.struchkov.example.hibernate.nbfe.problem;
+
+import dev.struchkov.example.hibernate.nbfe.problem.domain.Post;
+import dev.struchkov.example.hibernate.nbfe.problem.domain.PostComment;
+import dev.struchkov.example.hibernate.nbfe.problem.domain.Tag;
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+import jakarta.persistence.Persistence;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.LongStream;
+
+public class GeneratePost {
+
+    public static void main(String[] args) {
+
+        final EntityManagerFactory emf = Persistence.createEntityManagerFactory("Blog");
+        final EntityManager entityManager = emf.createEntityManager();
+
+        entityManager.getTransaction().begin();
+
+        for (long j = 0; j < 20; j++) {
+            final Tag tag = new Tag();
+            tag.setId(j);
+            tag.setName("Tag " + j);
+            entityManager.merge(tag);
+        }
+
+        entityManager.getTransaction().commit();
+
+        entityManager.getTransaction().begin();
+
+        final List<Tag> tags = entityManager.createQuery("SELECT t FROM Tag t where t.id IN :id", Tag.class)
+                .setParameter("id", LongStream.range(0, 19).boxed().collect(Collectors.toSet()))
+                .getResultList();
+
+        for (int i = 0; i < 50; i++) {
+            final Post post = new Post();
+            post.setTitle("Пост " + i);
+
+            for (int j = 0; j < 1000; j++) {
+                final PostComment postComment = new PostComment();
+                postComment.setReview("Комментарий " + j);
+                post.addComment(postComment);
+            }
+
+            tags.forEach(post::addTag);
+
+            entityManager.merge(post);
+        }
+
+        entityManager.getTransaction().commit();
+
+    }
+
+}

src/main/java/dev/struchkov/example/hibernate/nbfe/problem/domain/Tag.java

@@ -1,7 +1,6 @@
 package dev.struchkov.example.hibernate.nbfe.problem.domain;
 
 import jakarta.persistence.Entity;
-import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.Id;
 import lombok.Getter;
 import lombok.Setter;
@@ -12,7 +11,6 @@ import lombok.Setter;
 public class Tag {
 
     @Id
-    @GeneratedValue
     private Long id;
 
     private String name;