Question

我是hibernate的新手，并尝试在oracle db中映射已创建的表。在下面给出的代码中：

Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();

String hql = "FROM CrbtSubMasterDemo where rownum<20";
Query query = session.createQuery(hql);

List itr = query.list();
session.getTransaction().commit();

for (Iterator iterator = itr.iterator(); iterator.hasNext();)
{
System.out.println("[" + iterator.next() + "]");
}

当我运行此代码时。它首先给出了这个例外：


Apr 26, 2016 8:10:47 PM org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl processGetTableResults
INFO: HHH000262: Table not found: sdp.crbt_subscriber_master
Hibernate: create table sdp.crbt_subscriber_master (MSISDN varchar2(255) not null, STATUS varchar2(255), DATE_REGISTERED date, PLAN_INDICATOR number(10,0), RBT_CODE number(10,0), PASSWORD varchar2(255), TPIN varchar2(255), FREE_EVENTS_USED number(10,0), BLACK_LISTED number(10,0), LANGUAGE number(10,0), DEFAULT_GROUP_SETTING varchar2(255), DEFAULT_SINGLE_SETTING varchar2(255), DATE_SETTING_VALIDITY number(10,0), IMSI varchar2(255), LAST_CHARGED date, IS_MONTHLY_CHARGEABLE varchar2(255), CORP_ID number(10,0), SUB_TYPE varchar2(255), RENEW_MODE number(10,0), EXPIRY_DATE date, ACTIVE_FEATURES number(10,0), IN_USE_RBT number(10,0), UPDATE_TIME date, CORP_EXPIRY date, primary key (MSISDN))
Apr 26, 2016 8:10:47 PM org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleException
WARN: GenerationTarget encountered exception accepting command : Unable to execute command [create table sdp.crbt_subscriber_master (MSISDN varchar2(255) not null, STATUS varchar2(255), DATE_REGISTERED date, PLAN_INDICATOR number(10,0), RBT_CODE number(10,0), PASSWORD varchar2(255), TPIN varchar2(255), FREE_EVENTS_USED number(10,0), BLACK_LISTED number(10,0), LANGUAGE number(10,0), DEFAULT_GROUP_SETTING varchar2(255), DEFAULT_SINGLE_SETTING varchar2(255), DATE_SETTING_VALIDITY number(10,0), IMSI varchar2(255), LAST_CHARGED date, IS_MONTHLY_CHARGEABLE varchar2(255), CORP_ID number(10,0), SUB_TYPE varchar2(255), RENEW_MODE number(10,0), EXPIRY_DATE date, ACTIVE_FEATURES number(10,0), IN_USE_RBT number(10,0), UPDATE_TIME date, CORP_EXPIRY date, primary key (MSISDN))]
org.hibernate.tool.schema.spi.CommandAcceptanceException: Unable to execute command [create table sdp.crbt_subscriber_master (MSISDN varchar2(255) not null, STATUS varchar2(255), DATE_REGISTERED date, PLAN_INDICATOR number(10,0), RBT_CODE number(10,0), PASSWORD varchar2(255), TPIN varchar2(255), FREE_EVENTS_USED number(10,0), BLACK_LISTED number(10,0), LANGUAGE number(10,0), DEFAULT_GROUP_SETTING varchar2(255), DEFAULT_SINGLE_SETTING varchar2(255), DATE_SETTING_VALIDITY number(10,0), IMSI varchar2(255), LAST_CHARGED date, IS_MONTHLY_CHARGEABLE varchar2(255), CORP_ID number(10,0), SUB_TYPE varchar2(255), RENEW_MODE number(10,0), EXPIRY_DATE date, ACTIVE_FEATURES number(10,0), IN_USE_RBT number(10,0), UPDATE_TIME date, CORP_EXPIRY date, primary key (MSISDN))]
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:63)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.applySqlString(SchemaMigratorImpl.java:567)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.applySqlStrings(SchemaMigratorImpl.java:551)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.createTable(SchemaMigratorImpl.java:339)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.performMigration(SchemaMigratorImpl.java:257)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.doMigration(SchemaMigratorImpl.java:137)
    at org.hibernate.tool.schema.internal.SchemaMigratorImpl.doMigration(SchemaMigratorImpl.java:110)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:176)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:64)
    at org.hibernate.internal.SessionFactoryImpl.(SessionFactoryImpl.java:458)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:465)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at com.telemune.demoHibernate.QueryTester.(QueryTester.java:17)
    at com.telemune.demoHibernate.QueryTester.main(QueryTester.java:21)
Caused by: java.sql.SQLException: ORA-00955: name is already used by an existing object

    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288)
    at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:745)
    at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:210)
    at oracle.jdbc.driver.T4CStatement.executeForRows(T4CStatement.java:961)
    at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1190)
    at oracle.jdbc.driver.OracleStatement.executeInternal(OracleStatement.java:1726)
    at oracle.jdbc.driver.OracleStatement.execute(OracleStatement.java:1696)
    at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:51)
    ... 14 more

Apr 26, 2016 8:10:47 PM org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl processGetTableResults
INFO: HHH000262: Table not found: sdp.crbt_subscriber_master
Apr 26, 2016 8:10:47 PM org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl processGetTableResults
INFO: HHH000262: Table not found: sdp.crbt_subscriber_master



and then show the required result successfully.
But I want to know the reason for the Exception. Asking for help. I only know some things about hibenate, sorry if its a silly question.

sdp is the name of data base. and this is my mapping:

sdp

Answer 1

我认为问题是你在这里指定一个带有表名的模式名称

<class name="com.telemune.demoPojo.CrbtSubMasterDemo" 
  table="sdp.crbt_subscriber_master">

Hibernate将sdp.crbt_subscriber_master视为表名。

但是当Hibernate尝试执行create table sdp.crbt_subscriber_master()时，Oracle将sdp视为模式名称，将crbt_subscriber_master视为表名。

不知道如何为映射指定架构名称，但您可以按照此处所述进行尝试

Chapter 5. Basic O/R Mapping: mapping-declaration-class

<class name="com.telemune.demoPojo.CrbtSubMasterDemo" 
  schema="sdp" table="crbt_subscriber_master">

Answer 2

此处表名称区分大小写。存在不匹配。

INFO: HHH000262: Table not found: sdp.crbt_subscriber_master

数据库正试图获得crbt_subscriber_master，但您已经提供了

String hql = "FROM CrbtSubMasterDemo where rownum

您的问题在这里：

还有另一个问题。您错过了完美地添加声明hql。

使用此代码

String hql = "FROM CrbtSubMasterDemo where rownum";

而不是

String hql = "FROM CrbtSubMasterDemo where rownum

您还可以阅读本教程：ORA-00955: name is already being used by existing object tips

UPDATE：

hibernate.hbm2ddl.auto自动验证或导出架构DDL   创建SessionFactory时到数据库。使用create-drop，   关闭SessionFactory时将删除数据库模式   明确。

e.g。验证|更新|创建|创建降

所以可能的选项列表是，

验证：验证架构，不对数据库进行任何更改。

更新：更新架构。

创建：创建架构，销毁以前的数据。

create-drop ：在会话结束时删除架构。

所以，因为它已经创建了数据表。然后，如果您从配置中删除此属性，那么它将被解决。

<property name="hbm2ddl.auto">update</property>

但你可以尝试一下。这也将解决问题。

<property name="hbm2ddl.auto">validate</property>

或

<property name="hbm2ddl.auto">none</property>

有时空字符串'比'无'要好得多。要使用“无”，您将收到warning message: org.hibernate.cfg.SettingsFactory - Unrecognized value for "hibernate.hbm2ddl.auto": none

org.hibernate.tool.schema.spi.CommandAcceptanceException：无法执行命令

2 个答案:

您的问题在这里：

UPDATE：