Classes can be mapped to tables or views. Since views have many constraints and limited functionality (for example they do not have primary keys and reference keys), some views cannot be updated, and the mappings may not work properly in some cases.
There are some conditions that need to be met in order to generate mapping for a specific class:
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The Java source can be generated. This may not be possible if, for example, the visibility of the class is private.
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The class is persistent.
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The generation mode is not set to Generate ADT (abstract data type).
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If the class is an inner class, it must be static, and have public visibility. Hibernate should then be able to create instances of the class.
Hibernate-specific class mapping options can be defined in the Hibernate tab of the class property sheet:
|
Option |
Description |
|---|---|
|
Dynamic insert |
Specifies that INSERT SQL should be generated at runtime and will contain only the columns whose values are not null. Hibernate Tag: dynamic-insert |
|
Dynamic update |
Specifies that UPDATE SQL should be generated at runtime and will contain only the columns whose values have changed. Hibernate Tag: dynamic-update |
|
Select before update |
Specifies that Hibernate should never perform a SQL UPDATE unless it is certain that an object is actually modified. Hibernate Tag: select-before-update |
|
Default cascade type |
Specifies the default cascade style. Hibernate Tag: default-cascade |
|
Default access type |
Specifies the default access type (field or property) Hibernate Tag: default-access |
|
Proxy name |
Specifies an interface to use for lazy initializing proxies. Hibernate Tag: proxy |
|
Batch size |
Specifies a "batch size" for fetching instances of this class by identifier. Hibernate Tag: batch-size |
|
Check |
Specifies a SQL expression used to generate a multi-row check constraint for automatic schema generation. Hibernate Tag: check |
|
Polymorphism |
Specifies whether implicit or explicit query polymorphism is used. Hibernate Tag: polymorphism |
|
Schema name |
Specifies the name of the database schema. Hibernate Tag: schema |
|
Catalog name |
Specifies the name of the database catalog. Hibernate Tag: catalog |
|
Row id |
Specifies that Hibernate can use the ROWID column on databases which support it (for example, Oracle). Hibernate Tag: rowed |
|
Persister class name |
Specifies a custom persistence class. Hibernate Tag: persister |
|
Lazy |
Specifies that the class should be lazy fetching. Hibernate Tag: lazy |
|
Mutable |
Specifies that instances of the class are mutable. Hibernate Tag: mutable |
|
Abstract class |
Specifies that the class is abstract. Hibernate Tag: abstract |
|
Auto import |
Specifies that an unqualified class name can be used in a query Hibernate Tag: Auto-import |
|
Discriminator column |
Specifies the discriminator column or formula for polymorphic behavior in a one table per hierarchy mapping strategy. Hibernate Tag: discriminator |
|
Discriminator value |
Specifies a value that distinguishes individual subclasses, which are used for polymorphic behavior. Hibernate Tag: discriminator-value |
|
Discriminator type |
Specifies the discriminator type. Hibernate Tag: type |
|
Force usage of discriminator |
Forces Hibernate to specify allowed discriminator values even when retrieving all instances of the root class. Hibernate Tag: force |
|
Do not use discriminator in insert |
Forces Hibernate to not include the column in SQL INSERTs Hibernate Tag: insert |
|
Optimistic lock type |
Specifies an optimistic locking strategy. Hibernate Tag: optimistic-lock |
|
Optimistic lock column name |
Specifies the column used for optimistic locking. A field is also generated if this option is set. Hibernate Tag: version/ timestamp |
|
Optimistic lock unsaved value |
Specifies whether an unsaved value is null or undefined. Hibernate Tag: unsaved-value |