Package javax.persistence
Annotation 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
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Optional Element Summary
Modifier and TypeOptional ElementDescription(Optional) The SQL fragment that is used when generating the DDL for the column.boolean
(Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.int
(Optional) The column length.(Optional) The name of the column.boolean
(Optional) Whether the database column is nullable.int
(Optional) The precision for a decimal (exact numeric) column.int
(Optional) The scale for a decimal (exact numeric) column.(Optional) The name of the table that contains the column.boolean
(Optional) Whether the column is a unique key.boolean
(Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.
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Element Details
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name
String name(Optional) The name of the column. Defaults to the property or field name.- Default:
- ""
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unique
boolean unique(Optional) Whether the column is a unique key. This is a shortcut for theUniqueConstraint
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
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nullable
boolean nullable(Optional) Whether the database column is nullable.- Default:
- true
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insertable
boolean insertable(Optional) Whether the column is included in SQL INSERT statements generated by the persistence provider.- Default:
- true
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updatable
boolean updatable(Optional) Whether the column is included in SQL UPDATE statements generated by the persistence provider.- Default:
- true
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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.
- Default:
- ""
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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:
- ""
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length
int length(Optional) The column length. (Applies only if a string-valued column is used.)- Default:
- 255
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precision
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
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scale
int scale(Optional) The scale for a decimal (exact numeric) column. (Applies only if a decimal column is used.)- Default:
- 0
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