com.easycodebox.common.jpa

注释类型 JoinColumn

@Target(value={TYPE,METHOD,FIELD})
 @Retention(value=RUNTIME)
public @interface JoinColumn

Is used to specify a mapped column for joining an entity association.

   Example:

   @ManyToOne
   @JoinColumn(name="ADDR_ID")
   public Address getAddress() { return address; }
 

从以下版本开始:

Java Persistence 1.0

可选元素概要

可选元素

限定符和类型	可选元素和说明
boolean	insertable (Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.
String	name 表的列名，既有外键的表的列名。
boolean	nullable (Optional) Whether the foreign key column is nullable.
String	referencedColumnName 外键引用的表的列名，默认为外键引用表的主键列名
String	table (Optional) The name of the table that contains the column.
boolean	unique (Optional) Whether the property is a unique key.
boolean	updatable (Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.

元素详细资料

name

public abstract String name

表的列名，既有外键的表的列名。默认为主表表名_id

默认值:

""

referencedColumnName

public abstract String referencedColumnName

外键引用的表的列名，默认为外键引用表的主键列名

默认值:

""

unique

public abstract boolean unique

(Optional) Whether the property is a unique key. This is a shortcut for the UniqueConstraint annotation at the table level and is useful for when the unique key constraint is only a single field. It is not necessary to explicitly specify this for a join column that corresponds to a primary key that is part of a foreign key.

默认值:

false

nullable

public abstract boolean nullable

(Optional) Whether the foreign key column is nullable.

默认值:

true

insertable

public abstract boolean insertable

(Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.

默认值:

true

updatable

public abstract boolean updatable

(Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.

默认值:

true

table

public abstract String table

(Optional) The name of the table that contains the column. 如果此属性没有值，则自动使用有外键的表名

默认值:

""