hbm2ddl

I am looking at the Hibernate hbm2ddl.auto configuration property and its possible values: validate update create create-drop What do all these values do? The Hibernate Reference Documentation only talks briefly about create-drop , but doesn't say anything about the other values: hibernate.hbm2ddl.auto Automatically validates or exports schema DDL to the database when the SessionFactory is created. With create-drop , the database schema will be dropped when the SessionFactory is closed explicitly. e.g. validate | update | create | create-drop I found very useful explanations in these Stack

In Hibernate 4.x, I used to generate and export the schema as defined in annotated entities as follows (using Spring to find annotated entities on the class path): Connection connection = DriverManager.getConnection("jdbc:h2:mem:jooq-meta-extensions", "sa", ""); Configuration configuration = new Configuration() .setProperty("hibernate.dialect", "org.hibernate.dialect.H2Dialect"); // [...] adding annotated classes to Configuration here... configuration.generateSchemaCreationScript( Dialect.getDialect(configuration.getProperties())); SchemaExport export = new SchemaExport(configuration,

I couldn't find a reference on how to switch hbm2ddl off. Pascal Thivent Just omitting hibernate.hbm2ddl.auto defaults to Hibernate not doing anything. From the reference documentation: 1.1.4. Hibernate configuration The hbm2ddl.auto option 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. Setting hbm2ddl.auto to none (undocumented) might generate a warning, such as: org.hibernate.cfg.SettingsFactory - Unrecognized value for

I want to create database schema in hibernate first time. And further, if there is any modification in the schema, like addition of a new table or deletion of some column, I want to update the existing schema keeping the previous data intact. As per options given at this question , it looks like either I can create schema destroying the previous data, or I can update the schema. Is there any value which can do both? Jayasagar Actually I just checked <property name="hibernate.hbm2ddl.auto" value="update" /> is even creating tables for the first time and then later if table/schema exist it does

I'm trying to update existing table with hbm2ddl.auto = update. There is several columns in several tables where database column definitions changes from declaration in entities. Like @Column(name="mycolumn", nullable=false, length=10) private Long mycolumn; and 'mycolumn' bigint(20) not null default 0 in MySQL. Why hbm2ddl doesn't update such things? And is it possible to force such update? I want to say hbm2ddl to remove default value of column and change length of type. jeff hibernate.hbm2ddl.auto" value="update won't modify existing table column definitions. Doing some testing I found that