Java tutorial
/******************************************************************************* * Copyright (c) 2008 - 2013 Oracle Corporation. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 * which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.php. * * Contributors: * Linda DeMichiel - Java Persistence 2.1 * Linda DeMichiel - Java Persistence 2.0 * ******************************************************************************/ package javax.persistence; import java.lang.annotation.Target; import java.lang.annotation.Retention; import static java.lang.annotation.ElementType.FIELD; import static java.lang.annotation.ElementType.METHOD; import static java.lang.annotation.RetentionPolicy.RUNTIME; import static javax.persistence.ConstraintMode.PROVIDER_DEFAULT; /** * Specifies the mapping of associations. It is applied to the * owning side of an association. * * <p> A join table is typically used in the mapping of many-to-many * and unidirectional one-to-many associations. It may also be used to * map bidirectional many-to-one/one-to-many associations, * unidirectional many-to-one relationships, and one-to-one * associations (both bidirectional and unidirectional). * *<p>When a join table is used in mapping a relationship with an *embeddable class on the owning side of the relationship, the *containing entity rather than the embeddable class is considered the *owner of the relationship. * * <p> If the <code>JoinTable</code> annotation is missing, the * default values of the annotation elements apply. * The name of the join table is assumed to be the table names of the * associated primary tables concatenated together (owning side * first) using an underscore. * * <pre> * * Example: * * @JoinTable( * name="CUST_PHONE", * joinColumns= * @JoinColumn(name="CUST_ID", referencedColumnName="ID"), * inverseJoinColumns= * @JoinColumn(name="PHONE_ID", referencedColumnName="ID") * ) * </pre> * * @see JoinColumn * @see JoinColumns * * @since Java Persistence 1.0 */ @Target({ METHOD, FIELD }) @Retention(RUNTIME) public @interface JoinTable { /** * (Optional) The name of the join table. * * <p> Defaults to the concatenated names of * the two associated primary entity tables, * separated by an underscore. */ String name() default ""; /** (Optional) The catalog of the table. * <p> Defaults to the default catalog. */ String catalog() default ""; /** (Optional) The schema of the table. * <p> Defaults to the default schema for user. */ String schema() default ""; /** * (Optional) The foreign key columns * of the join table which reference the * primary table of the entity owning the * association. (I.e. the owning side of * the association). * * <p> Uses the same defaults as for {@link JoinColumn}. */ JoinColumn[] joinColumns() default {}; /** * (Optional) The foreign key columns * of the join table which reference the * primary table of the entity that does * not own the association. (I.e. the * inverse side of the association). * * <p> Uses the same defaults as for {@link JoinColumn}. */ JoinColumn[] inverseJoinColumns() default {}; /** * (Optional) Used to specify or control the generation of a * foreign key constraint for the columns corresponding to the * <code>joinColumns</code> element when table generation is in * effect. If both this element and the <code>foreignKey</code> * element of any of the <code>joinColumns</code> elements are * specified, the behavior is undefined. If no foreign key * annotation element is specified in either location, the * persistence provider's default foreign key strategy will * apply. * * @since Java Persistence 2.1 */ ForeignKey foreignKey() default @ForeignKey(PROVIDER_DEFAULT); /** * (Optional) Used to specify or control the generation of a * foreign key constraint for the columns corresponding to the * <code>inverseJoinColumns</code> element when table generation * is in effect. If both this element and the * <code>foreignKey</code> element of any of the * <code>inverseJoinColumns</code> elements are specified, the * behavior is undefined. If no foreign key annotation element * is specified in either location, the persistence provider's * default foreign key strategy will apply. * * @since Java Persistence 2.1 */ ForeignKey inverseForeignKey() default @ForeignKey(PROVIDER_DEFAULT); /** * (Optional) Unique constraints that are * to be placed on the table. These are * only used if table generation is in effect. * <p> Defaults to no additional constraints. */ UniqueConstraint[] uniqueConstraints() default {}; /** * (Optional) Indexes for the table. These are only used if * table generation is in effect. * * @since Java Persistence 2.1 */ Index[] indexes() default {}; }