Define Relationships

After selecting the tables and specifying selection criteria for the data, you must define the traversal path. That is, you select the relationships to be used and the direction in which the relationships are traversed—from parent to child, from child to parent, or in both directions—during the Extract Process.

The traversal path determines the sequence in which Move selects data from tables referenced in the Access Definition. Consider the database structure of the tables you selected for extracting: The traversal path of the four selected tables: CUSTOMERS, ORDERS, DETAILS, and ITEMS

In this diagram, the relationships between tables are represented by three-character codes consisting of the letter "R", the first letter of the parent table, and the first letter of the child table.

CUSTOMERS is the Start Table, because you want to extract a subset of CUSTOMER data. Based on the relationships between each pair of tables:

To obtain the desired set of data for this scenario, you will include relationships RCO and ROD in the Extract Process and specify the direction in which Move traverses them.

Use the options on the Relationships tab to define the traversal path for selecting data from the tables referenced in the Access Definition. All relationships between pairs of tables in the Table List are displayed. The parent table and the corresponding child table in each relationship is provided.

Access Definition Editor with the Relationships tab selected

Review Status

Each listed relationship has a status, which indicates:

New
Relationship is listed for the first time. The status of a relationship is New the first time the list is displayed after:
  • A new relationship between tables on the list is defined.
  • A table is added to the list.

(After you have viewed the relationship, the status is no longer New and is shown as blank the next time you display the Relationships tab.)

When you run the Extract Process, a warning message advises you of any new relationships. Although you may proceed despite the warning, it may be prudent to review the relationship usage list.

Blank
Relationship is defined and is not new to the list.
Ref
Relationship is ignored because the parent or child table is a reference or lookup table, as specified on the Tables tab.
Unknown
Relationship does not exist. This condition can occur when a change in the Default Qualifier causes a new set of tables and relationships to be referenced in the Access Definition. Relationships with Unknown status are ignored during a process. To remove a relationship in Unknown status, right-click the relationship and click Remove or Remove All Unknown in the shortcut menu.

The Use new relationships check box is selected by default to include all relationships with a New status in the Extract Process. If you clear this check box, you must manually select new relationships to include them in an Extract Process. Clearing the check box ensures that a completed Access Definition is not affected by the addition of a new relationship.

Select Relationships

The Select column determines whether a relationship is used in the Extract Process.

For this scenario, verify that check boxes for relationships RCO and ROD are selected.

Specify Options 1 and 2

You can use the Options check boxes to extend the traversal path:

For this scenario, only Option (1) is selected because no tables will be traversed from child to parent.