VIEW COMPOSING DEVICE

PURPOSE:To easily compose a view by using an ER chart and making a guidance in consideration of the relation of entity types shown in the ER chart. CONSTITUTION:When an entity type is selected in the ER chart on an ER chart display screen 1 by using a screen position selecting means 5, a view composition assisting means 2 converts the ER chart into a tree structure showing the relation of cardinality 1 by using the selected entity type as a root and displays it on a tree structure display screen 3. Further, when an attribute for view composition is selected for the displayed tree structure, the view composition assisting means 2 composes the view according to the selection result and displays it on a view display screen 4. Consequently, the entity type can be specified with the displayed tree structure and then attributes which are possibly in the target view are displayed in an easy-to-select state, so a user can easily compose a desired view.