javax.persistence.Column - JPA annotation
javax.persistence
Annotation Column
- Target:
- Fields (including property get methods)
Is used to specify 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:
- JPA 1.0
String columnDefinition
(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.
- Default value:
- ""
- Since:
- JPA 1.0
boolean insertable
(Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.
- Default value:
- true
- Since:
- JPA 1.0
int length
(Optional) The column length. (Applies only if a string-valued column is used.)
- Default value:
- 255
- Since:
- JPA 1.0
String name
(Optional) The name of the column. Defaults to the property or field name.
- Default value:
- ""
- Since:
- JPA 1.0
boolean nullable
(Optional) Whether the database column is nullable.
- Default value:
- true
- Since:
- JPA 1.0
int precision
(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.
- Default value:
- 0
- Since:
- JPA 1.0
int scale
(Optional) The scale for a decimal (exact numeric) column. (Applies only if a decimal column is used.)
- Default value:
- 0
- Since:
- JPA 1.0
String table
(Optional) The name of the table that contains the column. If absent the column is assumed to be in the primary table.
- Default value:
- ""
- Since:
- JPA 1.0
boolean unique
(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. - Default value:
- false
- Since:
- JPA 1.0
boolean updatable
(Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.
- Default value:
- true
- Since:
- JPA 1.0
