Column (EclipseLink 2.6.1, API Reference)

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

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

Optional Element Summary

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

- Element Detail
  - name
```
public abstract java.lang.String name
```
    (Optional) The name of the column. Defaults to the property or field name.
    
    Default:
    
    ""
  - unique
```
public abstract 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:
    
    false
  - nullable
```
public abstract boolean nullable
```
    (Optional) Whether the database column is nullable.
    
    Default:
    
    true
  - insertable
```
public abstract boolean insertable
```
    (Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.
    
    Default:
    
    true
  - updatable
```
public abstract boolean updatable
```
    (Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.
    
    Default:
    
    true
  - columnDefinition
```
public abstract java.lang.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:
    
    ""
  - table
```
public abstract java.lang.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:
    
    ""
  - length
```
public abstract int length
```
    (Optional) The column length. (Applies only if a string-valued column is used.)
    
    Default:
    
    255
  - precision
```
public abstract 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:
    
    0
  - scale
```
public abstract int scale
```
    (Optional) The scale for a decimal (exact numeric) column. (Applies only if a decimal column is used.)
    
    Default:
    
    0

Annotation Type Column

Optional Element Summary

Element Detail

name

unique

nullable

insertable

updatable

columnDefinition

table

length

precision

scale