Java 如何关闭 hbm2ddl？

How to turn off hbm2ddl?

提问by Alex

I couldn't find a reference on how to switch hbm2ddl off.

我找不到有关如何关闭 hbm2ddl 的参考。

采纳答案by Pascal Thivent

Just omitting hibernate.hbm2ddl.autodefaults to Hibernate not doing anything. From the reference documentation:

只是省略hibernate.hbm2ddl.auto默认 Hibernate 不做任何事情。从参考文档：

1.1.4. Hibernate configuration

The hbm2ddl.autooption turns on automatic generation of database schemas directly into the database. This can also be turned off by removing the configuration option, or redirected to a file with the help of the SchemaExport Ant task.

1.1.4. 休眠配置

该hbm2ddl.auto选项会直接将数据库模式自动生成到数据库中。 这也可以通过删除配置选项来关闭，或者在 SchemaExport Ant 任务的帮助下重定向到一个文件。

Setting hbm2ddl.autoto none(undocumented) might generate a warning, such as: org.hibernate.cfg.SettingsFactory - Unrecognized value for "hibernate.hbm2ddl.auto": none

设置hbm2ddl.auto为none（未记录）可能会产生警告，例如：org.hibernate.cfg.SettingsFactory - Unrecognized value for "hibernate.hbm2ddl.auto": none

回答by Bozho

in hibernate.properties

在 hibernate.properties 中

hibernate.hbm2ddl.auto=validate

Of course, the place to configure it depends on the way you configure your hibernate - if it is programatically, set the property there. If it is from hibernate.cfg.xml:

当然，配置它的位置取决于您配置休眠的方式 - 如果以编程方式，请在那里设置属性。如果它来自 hibernate.cfg.xml：

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

回答by Julien BRENELIERE

You can switch it off by :

您可以通过以下方式关闭它：

hibernate.hbm2ddl.auto=none

It's undocumented but priceless !

这是无证但无价的！

回答by Andres Saarem?ts

To get this one clear, one should look into the source of org.hibernate.cfg.SettingsFactory(you might see something else depending on the version used):

为了弄清楚这一点，应该查看以下来源org.hibernate.cfg.SettingsFactory（根据所使用的版本，您可能会看到其他内容）：

String autoSchemaExport = properties.getProperty( AvailableSettings.HBM2DDL_AUTO );
if ( "validate".equals(autoSchemaExport) ) {
    settings.setAutoValidateSchema( true );
}
else if ( "update".equals(autoSchemaExport) ) {
    settings.setAutoUpdateSchema( true );
}
else if ( "create".equals(autoSchemaExport) ) {
    settings.setAutoCreateSchema( true );
}
else if ( "create-drop".equals( autoSchemaExport ) ) {
    settings.setAutoCreateSchema( true );
    settings.setAutoDropSchema( true );
}
else if ( !StringHelper.isEmpty( autoSchemaExport ) ) {
    LOG.warn( "Unrecognized value for \"hibernate.hbm2ddl.auto\": " + autoSchemaExport );
}

In the org.hibernate.cfg.Settingsclass those variables are initialized as:

在org.hibernate.cfg.Settings类中，这些变量被初始化为：

private boolean autoCreateSchema;
private boolean autoDropSchema;
private boolean autoUpdateSchema;
private boolean autoValidateSchema;

so these default to false.

所以这些默认为false。

Omitting the hibernate.hbm2ddl.autosetting should switch off the HBM2DDL_AUTOfunctionality as would suggested hibernate.hbm2ddl.auto = none, but on the latter case you get a warning in the log.

省略hibernate.hbm2ddl.auto设置应该HBM2DDL_AUTO按照建议关闭功能hibernate.hbm2ddl.auto = none，但在后一种情况下，您会在日志中收到警告。

回答by gdrt

This property is not required. Just delete the hibernate.hbm2ddl.autoentry completely from the xml file.

此属性不是必需的。只需hibernate.hbm2ddl.auto从 xml 文件中完全删除条目。

回答by jstadler

If you enter an unsupported value it will tell you which ones are supported: o.h.b.i.SessionFactoryBuilderImpl : Unrecognized hbm2ddl_auto value : bla. Supported values include 'create', 'create-drop', 'update', 'none' and 'validate'. Ignoring

如果您输入不支持的值，它会告诉您支持哪些值： o.h.b.i.SessionFactoryBuilderImpl : Unrecognized hbm2ddl_auto value : bla. Supported values include 'create', 'create-drop', 'update', 'none' and 'validate'. Ignoring

And the value noneis the default, is officially supported and documented: https://docs.jboss.org/hibernate/orm/current/userguide/html_single/Hibernate_User_Guide.html#configurations-hbmddl

该值none是默认值，官方支持和记录：https: //docs.jboss.org/hibernate/orm/current/userguide/html_single/Hibernate_User_Guide.html#configurations-hbmddl