What are the 5 relation types and describe each one?
[table id=2 /]
•The ‘Known by’ relation defines a primary key field or identifying key field. You can have as many of these identifying keys defined as required for a unique record key.
•A ‘Qualified by’ relation is another identifying key field. These are used in situations where you may have data with the same unique primary keys and an additional qualification of a date or quantity field for instance. (An effective date or a quantity level break)
•The ‘Has’ relation is a simple attribute
•The ‘Owned by’ relation indicates a parent-child relationship between the two files. This is an identifying key field and is the key from the parent file (all the identifying key fields).
•Enforces referential integrity in the database
•Allows for Virtualization of fields (creating a Join Logical)
•Provides for automatic code generation of record selection capabilities (F4 or ? processing)
•The ‘Refers to’ relation is also a foreign key stored in the record, but it is not an identifying key field to the record.
•Enforces referential integrity in the database
•Allows for Virtualization of fields (creating a Join Logical)
•Provides for automatic code generation of record selection capabilities (F4 or ? processing
•The ‘Includes’ relation allows you to include a specified group of fields in the file.
•This group of fields is defined as a structure file
•The ‘Extended by’ relation is a relation intended to signify that a file has additional related data in another file. The extension file must still be entered using the ‘Owned by’ relation.
•This relation doesn’t add any attributes to the file (by default)
•Enforces referential integrity in the database (interactive functions will need to be ‘told’ to ignore this validation!)
•Indicates a one to one file relation.
•Allows for Virtualization
•Provides for automatic code generation of record selection capabilities (F4 or ? processing)
