Semantics of an object join
In the query language, one object can join with another object by using the dot notation. For example, item.category or category.spec.
The query language uses this convention to define the relationship between two objects in the IBM® Product Master data model. Only five of the eleven pre-defined objects in the query language can join with other objects: item, category, location, parent, and child. The objects location, parent, and child are the same type of objects as the object category is.
After joining with other object, the resulting object can join
with other objects again if the object is of item or category type.
For example:
- item.category
- item.category.spec
- item.category.item
- item.category.item.category
- item.category.item.category.item
- category.parent.child.parent.child.parent
Object: item
The item object in the query language can join with five objects.
| Object | Join with | Meaning |
|---|---|---|
| item | catalog | Catalog where the item is located |
| category | Categories that the item is mapped to | |
| location | Location that the item is mapped to | |
| step | Steps in the workflow that the item entry is checked out to | |
| logentry | Log entries related to the item |
Object: category
The category object in the query language can join with eight objects.
| Object | Category | Meaning |
|---|---|---|
| category | hierarchy | Hierarchy or category-tree where the category is located |
| category | Categories that the category is mapped to (category-to-category mapping) | |
| step | Steps in the workflow that the category entry is checked out to | |
| item | Item that is mapped to the category (item-to-category mapping) | |
| spec | Spec that is mapped to the category | |
| parent | Parent categories of the category in the hierarchy | |
| child | Child categories of the category in the hierarchy | |
| logentry | Log entries related to the category |