使用JPA

Question

當我使用下面的字段註釋實體不被持久化：

@Id
@TableGenerator(name = "comment_sequence", pkColumnValue = "comment_sequence")
@GeneratedValue(strategy = GenerationType.TABLE, generator = "comment_sequence")
private Long id_comment;

用於創建表的SQL是：

CREATE TABLE hibernate_sequences (sequence_name VARCHAR(255) NOT NULL, next_val bigint, PRIMARY KEY (sequence_name));
INSERT INTO hibernate_sequences VALUES ('comment_sequence', 1);

但實體根本不持續。想知道會發生什麼？我在上面介紹的代碼中做錯了什麼？

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編輯：

我壓抑在原崗位數的信息，我很抱歉（問半夜睡差不多= /）。

實體被正確地創建，如果我改變策略，以SEQUENCE並添加SQL CREATE SEQUENCE hibernate_sequence一切工作正常（其持續存在），但我想用TABLE策略連續召開各表順序hibernate_sequences。

我唯一的例外是TransactionRolledbackException歸因於集成測試中失敗測試導致的NullPointerException。沒有明確說明爲什麼不插入數據。

我使用hibernate.show_sql = true時，遇到下列休眠輸出：

... 

12:38:48,753 INFO [stdout] (pool-5-thread-1) Hibernate: 
12:38:48,754 INFO [stdout] (pool-5-thread-1)  insert 
12:38:48,755 INFO [stdout] (pool-5-thread-1)  into 
12:38:48,756 INFO [stdout] (pool-5-thread-1)   cm_comment 
12:38:48,757 INFO [stdout] (pool-5-thread-1)   (cd_status, ds_message, dt_alt, dt_inc, id_user_alt, id_user_inc, id_problem, id_comment) 
12:38:48,758 INFO [stdout] (pool-5-thread-1)  values 
12:38:48,759 INFO [stdout] (pool-5-thread-1)   (?, ?, ?, ?, ?, ?, ?, ?) 

12:38:48,766 INFO [stdout] (pool-5-thread-1) Hibernate: 
12:38:48,766 INFO [stdout] (pool-5-thread-1)  select 
12:38:48,767 INFO [stdout] (pool-5-thread-1)   commentent0_.id_comment as id1_6_, 
12:38:48,768 INFO [stdout] (pool-5-thread-1)   commentent0_.cd_status as cd2_6_, 
12:38:48,770 INFO [stdout] (pool-5-thread-1)   commentent0_.ds_message as ds3_6_, 
12:38:48,771 INFO [stdout] (pool-5-thread-1)   commentent0_.dt_alt as dt4_6_, 
12:38:48,772 INFO [stdout] (pool-5-thread-1)   commentent0_.dt_inc as dt5_6_, 
12:38:48,773 INFO [stdout] (pool-5-thread-1)   commentent0_.id_user_alt as id6_6_, 
12:38:48,774 INFO [stdout] (pool-5-thread-1)   commentent0_.id_user_inc as id7_6_, 
12:38:48,775 INFO [stdout] (pool-5-thread-1)   commentent0_.id_problem as id8_6_ 
12:38:48,776 INFO [stdout] (pool-5-thread-1)  from 
12:38:48,777 INFO [stdout] (pool-5-thread-1)   cm_comment commentent0_ 
12:38:48,778 INFO [stdout] (pool-5-thread-1)  where 
12:38:48,779 INFO [stdout] (pool-5-thread-1)   commentent0_.id_problem=? 

12:38:48,840 ERROR [org.jboss.arquillian.protocol.jmx.JMXTestRunner] (pool-5-thread-1) 
... 

java.lang.AssertionError: expected:<1> but was:<0> 

... 

我不知道這是否可以被相關，但在之前的測試中，我得到的錯誤：

12:50:36,510 INFO [org.jboss.as.ejb3] (pool-4-thread-1) JBAS014101: Failed to find SFSB instance with session ID {[-98, -17, -32, -33, 63, 107, 74, 59, -76, -127, -19, 29, 24, 45, -50, 5]} in cache

當我改變postgresql.conf爲log_statement = 'all'和運行應用程序，我沒有看到任何日誌後入住的pg_log目錄。所以我不確定如何啓用該選項。

我也是用的Arquillian，的Arquillian持久化API和JBoss的管理實例進行集成測試。我將更新標籤，因爲這可能與任何這些標籤有關。的TableGenerator

Answer 1

你的「宣言」沒有給出任何信息，關於哪個表應該查看/使用，所有你給予它是一個pkColumn名字....

嘗試：

@TableGenerator( name = "comment_sequence", table = "hibernate_sequences", pkColumnName = "sequence_name", valueColumnName = "next_val", pkColumnValue = "comment_sequence", allocationSize=1)

allocationSize=1大概應該是大於1？當你確認這是工作。 （上下行，如果你使用這種策略，並投入了大量的發電機到同一個表在DB注意潛在的鎖定問題 - 如果你的應用程序創建「大量的」實體）