JPA Annotation

Column

Target: METHOD, FIELD
Implemented Interfaces:
Annotation
Specifies the column mapped by the annotated persistent property or field.

If no Column annotation is explicitly specified, the default values apply.

Example 1:

 {@snippet :
Since:
JPA 1.0

Public Annotation Attributes

CheckConstraint[] check default {}
(Optional) Check constraints to be applied to the column.
These are only used if table generation is in effect.
Since:
JPA 3.2
String columnDefinition default ""
(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.

The specified DDL must be written in the native SQL dialect of the target database, and is not portable across databases.

Since:
JPA 1.0
String comment default ""
(Optional) A comment to be applied to the column.
This is only used if table generation is in effect.
Since:
JPA 3.2
boolean insertable default true
(Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.
Since:
JPA 1.0
int length default 255
(Optional) The column length.

Applies only to columns whose type is parameterized by length, for example, varchar or varbinary types.

Since:
JPA 1.0
String name default ""
(Optional) The name of the column.
Defaults to the property or field name.
Since:
JPA 1.0
boolean nullable default true
(Optional) Whether the database column is nullable.
Since:
JPA 1.0
String options default ""
(Optional) A SQL fragment appended to the generated DDL which declares this column.
May not be used in conjunction with Column.columnDefinition.

The specified DDL must be written in the native SQL dialect of the target database, and is not portable across databases.

Since:
JPA 3.2
int precision default 0
(Optional) The precision for a column of SQL type decimal or numeric, or of similar database-native type.

Applies only to columns of exact numeric type.

The default value 0 indicates that a provider-determined precision should be inferred.

Since:
JPA 1.0
int scale default 0
(Optional) The scale for a column of SQL type decimal or numeric, or of similar database-native type.

Applies only to columns of exact numeric type.

The default value 0 indicates that a provider-determined scale should be inferred.

Since:
JPA 1.0
int secondPrecision default -1
(Optional) The number of decimal digits to use for storing fractional seconds in a SQL time or timestamp column.

Applies only to columns of time or timestamp type.

The default value -1 indicates that fractional seconds should not be stored in a time column, or that the maximum number of digits supported by the database and JDBC driver should be stored in a timestamp column.

Since:
JPA 3.2
String table default ""
(Optional) The name of the table that contains the column.
If absent the column is assumed to be in the primary table.
Since:
JPA 1.0
boolean unique default false
(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 the primary key mapping and to constraints specified at the table level.
Since:
JPA 1.0
boolean updatable default true
(Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.
Since:
JPA 1.0