Report Models and the Model Designer 331 Expressions should have a familiar ring to them. Expressions in a report model take one or more source fields, and manipulate them with functions, operators, and constants to derive a calculated value. These expressions are just like expressions in Report Designer. They are based on , and automatically provide access to and . Functions from the namespace and references to other assemblies or custom code can be used, too. A good example of what could be an expression is the combination of FirstName and LastName to create a new field called Name. Folders Folders allow. | Report Models and the Model Designer 331 Expressions should have a familiar ring to them. Expressions in a report model take one or more source fields and manipulate them with functions operators and constants to derive a calculated value. These expressions are just like expressions in Report Designer. They are based on and automatically provide access to and . Functions from the namespace and references to other assemblies or custom code can be used too. A good example of what could be an expression is the combination of FirstName and LastName to create a new field called Name. Folders Folders allow you to group collections of entities. Folders can also contain other folders and perspectives. Folders allow you to add hierarchical information to the model. Folders can also be used to group items together regardless of hierarchical relationships. For example because Report Builder users can navigate folders in a manner similar to Windows Explorer you can move infrequently used items into a folder to hide them from the users. Perspectives Perspectives help to give us a narrower view or a view of a subset of the model. Perspectives can help limit users to see only information to which they have access. For example a company might have a model that contains information about all the financial data items for that company. One of the things perspectives can help us do is to limit what budgetary information users can see to only information about their departments budgets. Perspectives are contained in the model and the model designers and wizards don t create them for you. They have to be manually created and model items must be placed in them. Perspectives can contain other model objects such as entities folders roles source fields and expressions. Just placing items into a perspective does not exclude them from the rest of the models. Items can still be placed in other folders and perspectives. Creating a Model .
