javax.persistence
Annotation Type Column


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

Is used to specify a mapped column for a persistent property or field. If no Column annotation is specified, the default values are applied.

Author:
Emmanuel Bernard

Optional Element Summary
 String columnDefinition
          The SQL fragment that is used when generating the DDL for the column.
 boolean insertable
          Whether the column is included in SQL INSERT statements generated by the persistence provider.
 int length
          The column length.
 String name
          The name of the column.
 boolean nullable
          Whether the database column is nullable
 int precision
          The precision for a decimal (exact numeric) column.
 int scale
          The scale for a decimal (exact numeric) column.
 String table
          The name of the table that contains the column.
 boolean unique
          Whether the property is a unique key.
 boolean updatable
          Whether the column is included in SQL UPDATE statements generated by the persistence provider.
 

name

public abstract String name
The name of the column. Defaults to the property or field name

Default:
""

unique

public abstract boolean unique
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. This constraint applies in addition to any constraint entailed by primary key mapping and to constraints specified at the table level.

Default:
false

nullable

public abstract boolean nullable
Whether the database column is nullable

Default:
true

insertable

public abstract boolean insertable
Whether the column is included in SQL INSERT statements generated by the persistence provider.

Default:
true

updatable

public abstract boolean updatable
Whether the column is included in SQL UPDATE statements generated by the persistence provider.

Default:
true

columnDefinition

public abstract String columnDefinition
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:
""

table

public abstract String table
The name of the table that contains the column. If absent the column is assumed to be in the primary table.

Default:
""

length

public abstract int length
The column length. (Applies only if a string-valued column is used.)

Default:
255

precision

public abstract int precision
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:
0

scale

public abstract int scale
The scale for a decimal (exact numeric) column. (Applies only if a decimal column is used.)

Default:
0