IDs for repository items are requested from the appropriate IdSpace for the repository item. The id-space-names attribute in the primary table of an item descriptor specifies which IdSpaces supply repository IDs for items of that item type. For item types with single-column IDs, the default name for the IdSpace is the item descriptor name. For item types with multi-column IDs, the default name for the IdSpace is derived from the primary table name and ID column:
primary-table-name.id-column-names
For example, in an item descriptor defined like this:
<item-descriptor name="user">
<table name="users" type="primary" id-column-names="id">
properties...
</table>
</item-descriptor>
the default IdSpace would be named user. In an item descriptor with a composite repository ID defined like this:
<table name="user" type="primary" id-column-names="dept_id,emp_id">
properties...
</table>
the default IdSpaces would be named user.dept_id and user.emp_id. In any case, you can override the default IdSpace names using the id-space-names attribute in the item descriptor definition:
<table name="user" type="primary" id-column-names="dept_id,emp_id"
id-space-names="DepartmentId,EmployeeId">
properties...
</table>
See the ID Generators section of the Core Dynamo Services chapter in the ATG Programming Guide for more information about ID space names and how they affect the IDs of newly generated items.
