WEBDEV Concepts

Part 5: Databases 167 Shared link with a 1,n - 1,1 cardinality With this type of link: • each owner has at least one member (each supplier has at least one product). • each member has a single owner (each product has a single supplier). Complex link For a "complex" link, you need to define a relationship file . The relationship file will be automatically created. It will contain a unique key that includes the two keys of the related data files. The relationship file can also contain information specific to the link. A complex link includes two shared links. Example of complex link An order (Orders data file) can contain one or more products. A product (Product data file) can be used in several orders. In this case, a relationship file is required (OrderLine data file). The OrderLine data file contains: • a unique key containing the keys of Product and Orders. • the number of products ordered. 4 Possible operations in an analysis WEBDEV allows you to perform the following operations on an analysis: • Duplicating/Copying an LDM: Duplicating an LDM allows you to have two identical LDMs with different names. • Delete an LDM. • Rename an LDM. • Associate an LDM with a project. • Enlarge or reduce a LDM in the editor. • Move a LDM in the editor. WEBDEV allows you to perform the following operations on a data file found in the data model editor: • Duplicate/Copy a data file. • Delete a data file. • Rename a data file. WEBDEV allows you to perform the following operations on an item of a data file found in the data model editor: • Duplicate/Copy an item. • Delete an item. • Rename an item. For more details, see the online help.