Database Views

A Database View defines a table for viewing manipulating data in the database; these data may be derived from a single element or multiple elements. There is a row in the Database View table for each element that has a particular element type and meets the criteria defined by attribute filters. These Filters are similar in concept to those in the search grid. In addition, if element match criteria cannot be expressed using attribute filters, it is possible to define an expression for evaluation.

For example, a Database View could be derived from all Equipment elements in the current MDB with a description of ‘Vessel’. The user also specifies the required columns; each can be a database attribute or an expression run against the equipment element. The user can also specify how to navigate to related elements, such as the owning SITE or ZONE, and derive further columns from that element. This is similar in concept to a saved search except that editable columns may be derived from several elements.

Database Views may be defined and modified in the DICTIONARY database using Lexicon to set up new elements in a new ‘Database View World’ (DBVWWL/D). Their definition may alternatively be stored as a local settings file (similar to saved searches) or as part of an application. This allows:

• User defined Database Views for reports, ad-hoc working

• Project defined Database Views, shared via Global

• Application defined Database Views for specialist applications

The Editor is currently available in the LEXICON and TAGS modules, under Display > Database Views Editor.

Access to the full Editor is gained by selecting Element Views from the dropdown list in the View Definition Set area. For details, please refer to the Tags User Guide in Schematics.

Database Views are created automatically to represent element type structures so that users don’t have to define them to make element information accessible to the generic reporting tool. This means there is already a Database View for equipment elements with their attributes defined in columns.