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Java Persistence API (JPA) Extensions Reference for EclipseLink, Release 2.4
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@TenantDiscriminatorColumn

The @TenantDiscriminator annotation is used with the @Multitenant annotation and the SINGLE-TABLE mulitenant type to limit what a persistence context can access in single-table mulitenancy.


Annotation Elements

Table 2-67 describes this annotation's elements.

Table 2-67 @TenantDiscriminatorColumn Properties

Annotation Element Description Default

java.lang.String columnDefinition

(Optional) The SQL fragment that is used when generating the DDL for the discriminator column.

The provider-generated SQL to create a column of the specified discriminator type.

java.lang.String contextProperty

(Optional) The name of the context property to apply to the tenant discriminator column.

eclipselink.tenant-id

DiscriminatorType discriminatorType

(Optional) The type of object/column to use as a class discriminator.

javax.persistence.DiscriminatorType.STRING

int length

(Optional) The column length for String-based discriminator types.

The column length for String-based discriminator types. Ignored for other discriminator types.

java.lang.String name

(Optional) The name of column to be used for the tenant discriminator.

TENANT_ID

boolean primaryKey

Specifies that the tenant discriminator column is part of the primary key of the tables.

false

java.lang.String table

(Optional) The name of the table that contains the column.

The name of the table that contains the column. If absent the column is assumed to be in the primary table. This attribute must be specified if the column is on a secondary table.



Usage

To configure single-table multi-tenancy, you must specify both of the following:

Using Discriminator Columns

The following characteristics apply to discriminator columns:

Using Single-Table Multi-Tenancy in an Inheritance Hierarchy

Inheritance strategies are configured by specifying the inheritance type (see @javax.persistence.Inheritance). Single-table multi-tenancy can be used in an inheritance hierarchy, as follows:


Examples

Table 2-67 shows a number of uses of tenant discriminator columns.

Example 2-110 Using @TenantDiscriminatorColumn Annotation

/** Single tenant discriminator column **/
 
@Entity
@Table(name = "CUSTOMER")
@Multitenant
@TenantDiscriminatorColumn(name = "TENANT", contextProperty = "multi-tenant.id")
public Customer() {
  ...
}
 
 
/** Multiple tenant discriminator columns using multiple tables **/
 
@Entity
@Table(name = "EMPLOYEE")
@SecondaryTable(name = "RESPONSIBILITIES")
@Multitenant(SINGLE_TABLE)
@TenantDiscriminatorColumns({
    @TenantDiscriminatorColumn(name = "TENANT_ID", contextProperty = "employee-tenant.id", length = 20)
    @TenantDiscriminatorColumn(name = "TENANT_CODE", contextProperty = "employee-tenant.code", discriminatorType = STRING, table = "RESPONSIBILITIES")
  }
)
public Employee() {
  ...
}
 
 
/** Tenant discriminator column mapped as part of the primary key on the database **/
 
@Entity
@Table(name = "ADDRESS")
@Multitenant
@TenantDiscriminatorColumn(name = "TENANT", contextProperty = "tenant.id", primaryKey = true)
public Address() {
  ...
}
 
 
/** Mapped tenant discriminator column **/
 
@Entity
@Table(name = "Player")
@Multitenant
@TenantDiscriminatorColumn(name = "AGE", contextProperty = "tenant.age")
public Player() {
  ...
 
  @Basic
  @Column(name="AGE", insertable="false", updatable="false")
  public int age;
}

Example 2-111 shows the same mappings, using the <tenant-disciminator-column> XML element in the eclipselink-orm.xml file.

Example 2-111 Using <tenant-discriminator-column> XML

<!-- Single tenant discriminator column -->
 
<entity class="model.Customer">
  <multitenant>
    <tenant-discriminator-column name="TENANT context-property="multi-tenant.id""/>
  </multitenant>
  <table name="CUSTOMER"/>
  ...
</entity>
 
<!-- Multiple tenant discriminator columns using multiple tables -->
 
<entity class="model.Employee">
  <multitenant type="SINGLE_TABLE">
    <tenant-discriminator-column name="TENANT_ID" context-property="employee-tenant.id" length="20"/>
    <tenant-discriminator-column name="TENANT_CODE" context-property="employee-tenant.id" discriminator-type="STRING" table="RESPONSIBILITIES"/>
  </multitenant>
  <table name="EMPLOYEE"/>
  <secondary-table name="RESPONSIBILITIES"/>
  ...
</entity>
 
<!-- Tenant discriminator column mapped as part of the primary key on the database -->
 
<entity class="model.Address">
  <multitenant>
    <tenant-discriminator-column name="TENANT" context-property="multi-tenant.id" primary-key="true"/>
  </multitenant>
  <table name="ADDRESS"/>
  ...
</entity>
 
<!-- Mapped tenant discriminator column -->
 
<entity class="model.Player">
  <multi-tenant>
    <tenant-discriminator-column name="AGE" context-property="tenant.age"/>
  </multi-tenant>
  <table name="PLAYER"/>
  ...
  <attributes>
    <basic name="age" insertable="false" updatable="false">
      <column name="AGE"/>
    </basic>
    ...
  </attributes>
  ...
</entity>


See Also

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