This is about specifying a sequence in <join mapping.

Database : ORACLE.

Tables :

CREATE TABLE TASK (
TASK_CODE NUMBER(10,0) NOT NULL ENABLE,
TASK_ID VARCHAR2(250 BYTE) DEFAULT '' NOT NULL ENABLE,
TASK_NAME VARCHAR2(250 BYTE) DEFAULT '' NOT NULL ENABLE,
CONSTRAINT PK__TASK__58D1301D PRIMARY KEY (TASK_CODE) ENABLE
);

CREATE TABLE TASK_TIMELINE (
TASK_TIMELINE_CODE NUMBER(10,0) NOT NULL ENABLE,
TASK_CODE NUMBER(10,0) DEFAULT NULL,
SCHEDULED_START DATE DEFAULT NULL,
SCHEDULED_END DATE DEFAULT NULL,
CONSTRAINT PK__TASK_TIMELINE__011F1899 PRIMARY KEY (TASK_TIMELINE_CODE) ENABLE,
CONSTRAINT FK__TASK_TIME__TASK___0D84EF7E FOREIGN KEY (TASK_CODE)
REFERENCES TASK (TASK_CODE) ON DELETE CASCADE ENABLE
);

Primary Key description :

TASK_CODE (PRIMARY KEY, SEQUENCE IN ORACLE, AUTOINCR. IN MYSQL, IDENTITY IN MSSQL)

TASK_TIMELINE_CODE (PRIMARY KEY, SEQUENCE IN ORACLE, AUTOINCR. IN MYSQL, IDENTITY IN MSSQL)

<class name="ProjectData" table="task">
<id name="primaryKey" column="TASK_CODE">
<generator class="native">
<param name="sequence">S_TASK</param>
</generator>
</id>

<property name="ID" column="TASK_ID" update="false"/>
<property name="name" column="TASK_NAME"/>

<join table="task_timeline" fetch="join">
<key column="TASK_CODE"/>
<property name="startDate" column="SCHEDULED_START"/>
<property name="endDate" column="SCHEDULED_END"/>
</join>
</class>

I am trying to insert a record in table 'task' and 'task_timeline' using mapped class 'ProjectData'.

I have sequences for tables 'task' and 'task_timeline' to generate primary keys. I specify the sequence for 'task' as following :

<generator class="native">
<param name="sequence">S_TASK</param>
</generator>

When a record is inserted into task it must also insert a record into task_timeline using the join.
How do I specify the sequence name for the join table task_timeline.

I tried with many-to-one but it fails to insert the primary key of task into task_timeline because task_codeof task is mapped twice, once as <id> and once as <many-to-one> with insert="false" update="false" to avoid repeated mapping on that column.

What are the alternatives for achieving these type of inserts using <join> where joined table also has its own primary key and a sequence.

This works perfectly with MySQL and MSSQL servers and in our context join is required and <set>, <bag> or other such collections.