Examples

Chapter 4 Building Physical Diagrams

Examples

The following examples illustrate how using the auto-reuse columns and auto-migrate columns options affects the creation of references.

Matching child table column exists

The following table shows the results of migrating primary key columns to a child table that contains a matching column for one of the primary key columns. The original two tables are also shown below:

Auto-reuse	Auto-migrate	Description of child table
Selected	Selected	Col_1 is reused and Col_2 is created
Not selected	Selected	T1_Col_1 is created and Col_2 is created
Selected	Not selected	Col_1 is reused and Col_2 is not created
Not selected	Not selected	No column is reused and no column is created

Matching child table column is already a FK column

The following table shows the results of migrating primary key columns to a child table that contains a matching child table column that is already a foreign key column for another table. The original two tables are also shown below:

Auto-reuse	Auto-migrate	Description of child table
Selected	Selected	T1_Col_1 is created and Col_2 is created
Not selected	Selected	T1_Col_1 is created and Col_2 is created
Selected	Not selected	No columns are reused or created
Not selected	Not selected	No columns are reused or created

Notes:

By default, only the properties of the primary key column are migrated to the foreign key. If the primary key column is attached to a domain, the domain will not be migrated to the new foreign key column unless the Enforce non-divergence option model option is selected (see Enforcing non-divergence from a domain in a data model).

The following table shows the results of changing references when you have selected the auto-migrate columns option:

Action	Result
Modify reference attach point	Migrate primary key in parent table to foreign key in child table Delete unused foreign key columns Modify reference join
Delete primary key	Delete corresponding foreign key and reference join

Migrate primary key in parent table to foreign key in child table

Delete unused foreign key columns

Modify reference join

Action	Result
Modify reference attach point	Migrate primary key in parent table to foreign key in child table Delete unused foreign key columns Modify reference join
Delete primary key	Delete corresponding foreign key and reference join

For more information on other model options for references, see "Setting PDM Model Options" section in the "Customizing the PDM Environment" chapter.