Module jakarta.persistence
Package jakarta.persistence

Annotation Interface Column

@Target({METHOD,FIELD}) @Retention(RUNTIME) public @interface Column
Specifies the column mapped by the annotated persistent property or field.

If no Column annotation is explicitly 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; }

Portable applications which make use of schema generation should explicitly specify the precision() and scale() of columns of type numeric or decimal.

Since:
1.0

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    CheckConstraint[]
    check
    (Optional) Check constraints to be applied to the column.
    String
    columnDefinition
    (Optional) The SQL fragment that is used when generating the DDL for the column.
    String
    comment
    (Optional) A comment to be applied to 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.
    String
    name
    (Optional) The name of the column.
    boolean
    nullable
    (Optional) Whether the database column is nullable.
    String
    options
    (Optional) A SQL fragment appended to the generated DDL which declares this column.
    int
    precision
    (Optional) The precision for a column of SQL type decimal or numeric, or of similar database-native type.
    int
    scale
    (Optional) The scale for a column of SQL type decimal or numeric, or of similar database-native type.
    int
    secondPrecision
    (Optional) The number of decimal digits to use for storing fractional seconds in a SQL time or timestamp column.
    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 Details

    • name

      String name
      (Optional) The name of the column. Defaults to the property or field name.
      Default:
      ""

    • unique

      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 the primary key mapping and to constraints specified at the table level.
      Default:
      false

    • nullable

      boolean nullable
      (Optional) Whether the database column is nullable.
      Default:
      true

    • insertable

      boolean insertable
      (Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.
      Default:
      true

    • updatable

      boolean updatable
      (Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.
      Default:
      true

    • columnDefinition

      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.

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

      Default:
      ""

    • options

      String options
      (Optional) A SQL fragment appended to the generated DDL which declares this column. May not be used in conjunction with columnDefinition().

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

      Since:
      3.2
      Default:
      ""

    • table

      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

      int length
      (Optional) The column length.

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

      Default:
      255

    • precision

      int precision
      (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.

      Default:
      0

    • scale

      int scale
      (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.

      Default:
      0

    • secondPrecision

      int secondPrecision
      (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:
      3.2
      Default:
      -1

    • check

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

    • comment

      String comment
      (Optional) A comment to be applied to the column. This is only used if table generation is in effect.
      Since:
      3.2
      Default:
      ""