我試圖在資料庫(kù)的 Comment 表中使用帖子 id 的外鍵保留 6 條評(píng)論，但最後 3 條評(píng)論使用新添加的外鍵覆蓋了前 3 條評(píng)論。
測(cè)試類別：
Comments comments = new Comments("1st Comment", new Date(System.currentTimeMillis()));
Comments comments2 = new Comments("2st Comment", new Date(System.currentTimeMillis()));
Comments comments3 = new Comments("3st Comment", new Date(System.currentTimeMillis()));
ArrayList<Comments> arrayList = new ArrayList<>();
arrayList.add(comments);
arrayList.add(comments2);
arrayList.add(comments3);
// Insert Without Comment
Post post1 = new Post("1st Post", "1st Post Description", new ArrayList<Comments>(), new Date(System.currentTimeMillis()));
postReposetory.save(post1);
// Insert With Comment
Post post2 = new Post("2st Post", "2st Post Description", arrayList, new Date(System.currentTimeMillis()));
postReposetory.save(post2);
// Update (Insert Comment)
post1.setComments(arrayList);
post1.setUpdatedAt(new Date(System.currentTimeMillis()));
postReposetory.save(post1); 
2
0
0
您總共建立了 3 個(gè)評(píng)論實(shí)例（因此資料庫(kù)表中有 3 筆記錄），而不是每個(gè)貼文 3 個(gè)實(shí)例。
當(dāng)您更新 post1 評(píng)論時(shí)，您會(huì)將 post2 評(píng)論作為參數(shù)，因此從 comments 到 post2 的外鍵將變更為 post1。
如果您希望每個(gè)貼文有 3 則評(píng)論，則總共需要 6 個(gè)評(píng)論實(shí)例（2 個(gè)貼文 * 3 則評(píng)論）。
發(fā)生這種情況是因?yàn)槟胖昧讼嗤脑]釋對(duì)象，然後 hibernate 認(rèn)為您想要將註釋的連接從 post2 更改為 post1。
因此您必須重新建構(gòu)這三個(gè)註解。
Comments comments = new Comments("1st Comment", new Date(System.currentTimeMillis()));
Comments comments2 = new Comments("2st Comment", new Date(System.currentTimeMillis()));
Comments comments3 = new Comments("3st Comment", new Date(System.currentTimeMillis()));
ArrayList arrayList = new ArrayList();
arrayList.add(comments);
arrayList.add(comments2);
arrayList.add(comments3);
// Insert With Comment
Post post1 = new Post("1st Post", "1st Post Description", new ArrayList(), new Date(System.currentTimeMillis()));
postReposetory.save(post1);
// Insert Without Comment
Post post2 = new Post("2st Post", "2st Post Description", arrayList, new Date(System.currentTimeMillis()));
postReposetory.save(post2);
// Update (Insert Comment)
comments = new Comments("1st Comment", new Date(System.currentTimeMillis()));
comments2 = new Comments("2st Comment", new Date(System.currentTimeMillis()));
comments3 = new Comments("3st Comment", new Date(System.currentTimeMillis()));
post1.setComments(List.of(comments, comments2, comments3));
post1.setUpdatedAt(new Date(System.currentTimeMillis()));
postReposetory.save(post1);
這樣就創(chuàng)建了另外三個(gè)物件用於評(píng)論。
