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
/*******************************************************************************
* 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.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
Specifies the mapped column for a persistent property or field.
If no Column annotation is specified, the default values apply.
Example 1:
@Column(name="DESC", nullable=false, length=512)
public String getDescription() { return description; }
Example 2:
@Column(name="DESC",
columnDefinition="CLOB NOT NULL",
table="EMP_DETAIL")
@Lob
public String getDescription() { return description; }
Example 3:
@Column(name="ORDER_COST", updatable=false, precision=12, scale=2)
public BigDecimal getCost() { return cost; }
Since: Java Persistence 1.0
/**
* Specifies the mapped column for a persistent property or field.
* If no <code>Column</code> annotation is specified, the default values apply.
*
* <blockquote><pre>
* Example 1:
*
* @Column(name="DESC", nullable=false, length=512)
* public String getDescription() { return description; }
*
* Example 2:
*
* @Column(name="DESC",
* columnDefinition="CLOB NOT NULL",
* table="EMP_DETAIL")
* @Lob
* public String getDescription() { return description; }
*
* Example 3:
*
* @Column(name="ORDER_COST", updatable=false, precision=12, scale=2)
* public BigDecimal getCost() { return cost; }
*
* </pre></blockquote>
*
*
* @since Java Persistence 1.0
*/
@Target({METHOD, FIELD})
@Retention(RUNTIME)
public @interface Column {
(Optional) The name of the column. Defaults to
the property or field name.
/**
* (Optional) The name of the column. Defaults to
* the property or field name.
*/
String name() default "";
(Optional) Whether the column 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
corresponds to only a single column. This constraint applies
in addition to any constraint entailed by primary key mapping and
to constraints specified at the table level.
/**
* (Optional) Whether the column is a unique key. This is a
* shortcut for the <code>UniqueConstraint</code> annotation at the table
* level and is useful for when the unique key constraint
* corresponds to only a single column. This constraint applies
* in addition to any constraint entailed by primary key mapping and
* to constraints specified at the table level.
*/
boolean unique() default false;
(Optional) Whether the database column is nullable.
/**
* (Optional) Whether the database column is nullable.
*/
boolean nullable() default true;
(Optional) Whether the column is included in SQL INSERT
statements generated by the persistence provider.
/**
* (Optional) Whether the column is included in SQL INSERT
* statements generated by the persistence provider.
*/
boolean insertable() default true;
(Optional) Whether the column is included in SQL UPDATE
statements generated by the persistence provider.
/**
* (Optional) Whether the column is included in SQL UPDATE
* statements generated by the persistence provider.
*/
boolean updatable() default true;
(Optional) The SQL fragment that is used when
generating the DDL for the column.
Defaults to the generated SQL to create a
column of the inferred type.
/**
* (Optional) The SQL fragment that is used when
* generating the DDL for the column.
* <p> Defaults to the generated SQL to create a
* column of the inferred type.
*/
String columnDefinition() default "";
(Optional) The name of the table that contains the column.
If absent the column is assumed to be in the primary table.
/**
* (Optional) The name of the table that contains the column.
* If absent the column is assumed to be in the primary table.
*/
String table() default "";
(Optional) The column length. (Applies only if a
string-valued column is used.)
/**
* (Optional) The column length. (Applies only if a
* string-valued column is used.)
*/
int length() default 255;
(Optional) The precision for a decimal (exact numeric)
column. (Applies only if a decimal column is used.)
Value must be set by developer if used when generating
the DDL for the column.
/**
* (Optional) The precision for a decimal (exact numeric)
* column. (Applies only if a decimal column is used.)
* Value must be set by developer if used when generating
* the DDL for the column.
*/
int precision() default 0;
(Optional) The scale for a decimal (exact numeric) column.
(Applies only if a decimal column is used.)
/**
* (Optional) The scale for a decimal (exact numeric) column.
* (Applies only if a decimal column is used.)
*/
int scale() default 0;
}