项目顶用到的JPA Annotation 之一：DiscriminatorColumn

Example:@Entity @Table(name="CUST")
@Inheritance(strategy=SINGLE_TABLE)
@DiscriminatorColumn(name="DISC", discriminatorType=STRING, length=20)
public class Customer { ... } ?

@Entity public class ValuedCustomer extends Customer { ... }

Since:

JPA 1.0

See Also:

DiscriminatorValue(Optional) The SQL fragment that is used when generating the DDL for the discriminator column.

Defaults to the provider-generated SQL to create a column of the specified discriminator type.

Default value:

""

Since:

JPA 1.0(Optional) The type of object/column to use as a class discriminator. Defaults to(Optional) The column length for String-based discriminator types. Ignored for other discriminator types.

Default value:

31

Since:

JPA 1.0(Optional) The name of column to be used for the discriminator.

Default value:

"DTYPE"

Since:

JPA 1.0