Relation Types and Behavior

The system supports three relationship types:

One-to-One	In a one-to-one relationship, a record in Component A can have no more than one matching record in Component B, and vice versa.
One-to-Many (or Many-to-One)	A one-to-many relationship is the most common type of relationship. In this type of relationship, a record in Component A can have many matching records in Component B, but a record in Component B can have only one matching record in Component A.
Many-to-Many	In a many-to-many relationship, a record in Component A can have many matching records in Component B, and vice versa.

In order to determine the type and behavior of the relationships, the following questions are available when defining a relationship.

Q1	One [THIS component] record can have how many [RELATED component] records?	1/Many
Q2	One [RELATED component] record can have how many [THIS component] records?	1/Many
Q3	Delete [THIS component] record(s) when [RELATED component] record(s) are deleted?	Yes/No
Q4	Delete [RELATED component] records(s) when [THIS component] record(s) are deleted?	Yes/No

Depending on the answers for the questions, labeled Q1 to Q4 above, the relationship type and delete behavior will be determined as follows:

Q1	Q2	Q4	Q3	Relationship Type	Delete Behavior	Relationship Type in Prior Versions	Storage of Foreign Key
1	1	No	No	One-to-One	No records are deleted	One-to-One; Referenced	On the component where the relationship has been created.
1	1	Yes	No	One-to-One	Record from THIS Component is deleted when the record from the RELATED Component is deleted.	One-to-One; Contained by Associative	On the component where the relationship has been created.
1	1	No	Yes	One-to-One	Record from RELATED Component is deleted when the record from the THIS Component is deleted.	One-to-One; Contained by Primary	On the component where the relationship has been created.
1	1	Yes	Yes	One-to-One	Record from RELATED Component is deleted when the record from the THIS Component is deleted and vice versa. This depends on which record is deleted first.	One-to-One	On the component where the relationship has been created.
Many	1	No	No	Many-to-One	No Records are deleted	Many-to-one; Referenced	On the component where the relationship has been created
Many	1	No	Yes	Many-to-One	Records from RELATED Component are deleted when the record from the THIS Component is deleted and no other RELATED record(s) are linked to THIS record.	Many-to-one; Contained by Primary	On the component where the relationship has been created
Many	1	Yes	No	Many-to-One	Records from THIS Component are deleted when the record from the RELATED Component is deleted.	Many-to-One	On the component where the relationship has been created
Many	1	Yes	Yes	Many-to-One	This depends on which record is deleted first. If the record from THIS Component is deleted first then the records from the RELATED Component are deleted when no other records are linked to it. Otherwise if the record from the RELATED Component is deleted first, then all records from THIS Component are deleted.	Many-to-One	On the component where the relationship has been created
1	Many	No	No	One-to-Many	No records are deleted.	One-to-Many	On the related component. (Associative)
1	Many	No	Yes	One-to-Many	Records from RELATED Component are deleted when the record from the THIS Component is deleted.	One-to-many; Contained by Primary	On the related component. (Associative)
1	Many	Yes	No	One-to-Many	Records from THIS Component are deleted when the record from the RELATED Component is deleted and no other records are linked to THIS record.	One-to-many; Contained by Associative	On the related component. (Associative)
1	Many	Yes	Yes	One-to-Many	This depends on which record is deleted first. If the record from RELATED Component is deleted first then the records from the THIS Component are deleted when no other records are linked to it. If the record from the THIS Component is deleted first; then all records from RELATED Component are deleted.	One-to-many	On the related component. (Associative)
Many	Many	No	No	Many-to-Many	No records are deleted	Many-to-many; Referenced	Not stored in the components. Uses the table 'bms_component_links'
Many	Many	Yes	No	Many-to-Many	Records from THIS Component are deleted when the record from the RELATED Component is deleted and no other records are linked to THIS record.	Many-to-many; Owned by Associative	Not stored in the components. Uses the table 'bms_component_links'
Many	Many	No	Yes	Many-to-Many	Records from RELATED Component are deleted when the record from the THIS Component is deleted and no other records are linked to RELATED record.	Many-to-many; Owned by Primary	Not stored in the components. Uses the table 'bms_component_links'
Many	Many	Yes	Yes	Many-to-Many	Records from RELATED Component is deleted when all the records from the THIS Component is deleted and vice versa.	Many-to-many	Not stored in the components. Uses the table 'bms_component_links'