birt barcode tool Java Persistence API annotations in Java

Printer ECC200 in Java Java Persistence API annotations

The following annotations are used to define domain objects such as entities, embedded objects, and entity identity. javax.persistence.Entity Marks a POJO as a JPA entity.

@Target(TYPE) @Retention(RUNTIME) public @interface Entity { String name() default ""; }

javax.persistence.Embeddable Marks a POJO as an embeddable object (stored as a part of another entity).

@Target({TYPE}) @Retention(RUNTIME) public @interface Embeddable {}

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Embedded {}

javax.persistence.Id Denotes a persistence field or property that is the unique identifier for an entity.

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Id {}

@Target({TYPE}) @Retention(RUNTIME) public @interface IdClass { Class value(); }

@Target({TYPE}) @Retention(RUNTIME) public @interface EmbeddedId {}

These annotations are used to define entity data. javax.persistence.Transient Marks a field or property as transient (not persisted).

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Transient {}

javax.persistence.Lob Specifies that a persistence field or property be mapped to a large object type (BLOB or CLOB) in the database.

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Lob {}

javax.persistence.Temporal Specifies the mapping data type of a persistence field or property as java.util. Date or java.util.Calendar.

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Temporal { TemporalType value(); } public enum TemporalType { java.sql.Date DATE, java.sql.Time TIME, TIMESTAMP java.sql.Timestamp }

javax.persistence.Enumerated Denotes options for a persistence field or property of type enumerated.

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Enumerated { EnumType value() default ORDINAL; } public enum EnumType { ORDINAL, STRING }

C.2.3 Mapping entity data The annotations in this section are used to map entity data to the database.

@Target({TYPE}) @Retention(RUNTIME) public @interface Table { String name() default ""; Table catalog String catalog() default ""; Table schema String schema() default ""; UniqueConstraint[] uniqueConstraints() default {}; }

@Target({TYPE}) @Retention(RUNTIME) public @interface SecondaryTable { String name(); Table catalog String catalog() default ""; String schema() default ""; PrimaryKeyJoinColumn[] pkJoinColumns() default {}; UniqueConstraint[] uniqueConstraints() default {}; }

javax.persistence.UniqueConstraint Defines a unique constraint for a table used for entity mapping.

@Target({}) @Retention(RUNTIME) public @interface UniqueConstraint { String[] columnNames(); }

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Column { String name() default ""; boolean unique() default false; boolean nullable() default true; boolean insertable() default true; boolean updatable() default true; Column DDL String columnDefinition() default ""; String table() default ""; int length() default 255; Decimal precision int precision() default 0; int scale() default 0; Decimal scale }

javax.persistence.Basic Specifies some simple mapping attributes. Can be used with any association mapping or specify the fetch type for a field or property.

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface Basic { FetchType fetch() default EAGER; boolean optional() default true; }

javax.persistence.AttributeOverride Overrides the mapping of an entity property or field. This annotation is not discussed in this book. We encourage you to explore it on your own.

@Target({TYPE, METHOD, FIELD}) @Retention(RUNTIME) public @interface AttributeOverride { String name(); Column column(); }

javax.persistence.AttributeOverrides Specifies multiple mapping overrides. This annotation is not discussed in this book. We encourage you to explore it on your own.

@Target({TYPE, METHOD, FIELD}) @Retention(RUNTIME) public @interface AttributeOverrides { AttributeOverride[] value(); }

javax.persistence.GeneratedValue Used for automatic generation of values; typically used for primary keys.

@Target({METHOD, FIELD}) @Retention(RUNTIME) public @interface GeneratedValue { GenerationType strategy() default AUTO; String generator() default ""; } public enum GenerationType { TABLE, SEQUENCE, IDENTITY, AUTO }

javax.persistence.TableGenerator Denotes a generator that may be used for automatic key generation using a sequence table.

@Target({TYPE, METHOD, FIELD}) @Retention(RUNTIME) public @interface TableGenerator { Unique generator name String name(); String table() default "";

Table catalog String catalog() default ""; String schema() default ""; Table schema String pkColumnName() default ""; String valueColumnName() default ""; String pkColumnValue() default ""; int initialValue() default 0; Amount to increment by int allocationSize() default 50; UniqueConstraint[] uniqueConstraints() default {};

javax.persistence.SequenceGenerator Denotes a generator that may be used for automatic key generation using a database sequence.

@Target({TYPE, METHOD, FIELD}) @Retention(RUNTIME) public @interface SequenceGenerator { Unique generator name String name(); String sequenceName() default ""; Name of database sequence int initialValue() default 1; int allocationSize() default 50; Amount to increment by }