This annotation specifies the settings of the generator that creates the primary key.

The following settings are required when using @TableGenerator:

• Specify GenerationType.TABLE in the strategy element of @GeneratedValue.
• Set up the name specified in the generator element of @GeneratedValue to the name element of @TableGenerator.

The table generator is specified in the fields or properties of the entity class or primary key. The scope of the generator name is enabled in the persistence unit.

Use the rows of the generator table when generating the primary key value in an entity.

When creating a table for managing the sequence, specify a positive integer in the initial value. If 0 is specified in the initial value, the primary key will be generated from 1.

The applicable targets are class, method, and field.

The following table lists the elements of @TableGenerator:

Element name	Optional/Required	Element description
name	Required	This element specifies the generator name for the primary key value.
table	Optional	This element specifies the name of the table that maintains the generated primary key values.
catalog	Optional	This element specifies the catalog name of the table that maintains the generated primary key values. Note that Cosminexus JPA provider does not support this attribute.
schema	Optional	This element specifies the schema name of the table that maintains the generated primary key values.
pkColumnName	Optional	This element specifies the primary key column name of the table that maintains the generated primary key values.
valueColumnName	Optional	This element specifies the column name that maintains the final generated value.
pkColumnValue	Optional	This element specifies the primary key value of the table that maintains the generated primary key values.
initialValue	Optional	This element specifies the value used for initializing the column that maintains the recent generated values. Note that Cosminexus JPA provider does not support this attribute. Ignore when the value is specified.
allocationSize	Optional	This element specifies the size of allocating the primary key value from the generator.
uniqueConstraints	Optional	This element specifies the unique key constraints in the table that maintains the generated primary key values. Note that Cosminexus JPA provider does not support this attribute. Ignore when the value is specified.

The details of attributes that are supported with Cosminexus JPA provider are as follows:

(a) name element

Type

String

Description

This element specifies the generator name for the primary key value.

The value that can be specified is a character string.

Default value

None

(b) table element

Type

String

Description

This element specifies the name of the table that maintains the generated primary key values.

The table name that can be specified depends on the database specifications.

Default value

"SEQUENCE"

(c) schema element

Type

String

Description

This element specifies the schema name of the table that maintains the generated primary key values.

The schema name that can be specified depends on the database specifications.

Default value

Default schema name of the database used

(d) pkColumnName element

Type

String

Description

This element specifies the primary key column name of the table that maintains the generated primary key values.

The column name that can be specified depends on the database specifications.

Default value

"SEQ_NAME"

(e) valueColumnName element

Type

String

Description

This element specifies the column name that maintains the final generated value.

The column name that can be specified depends on the database specifications.

Default value

"SEQ_COUNT"

(f) pkColumnValue element

Type

String

Description

This element specifies the primary key value of the table that maintains the generated primary key values.

The value that can be specified depends on the type of column of the generated primary key.

Default value

Character string specified in the name element

(g) allocationSize element

Type

int

Description

This element specifies the allocation size of the primary key value from the generator.

The value that can be specified is a numeric value that is at least one more than the int type.

Note that you can specify the maximum value used during the execution in this element. If you specify a large value for acquiring the management area of the sequence number, the java.lang.OutOfMemoryError exception will occur during the execution.

Default value

50