Introducing the Draft Database

The top-level graphical elements in the Draft Database hierarchy are shown below.

Draft Database Hierarchy - Principal Graphic Elements

Figure 3:1 Draft Database Hierarchy - Principal Graphic Elements

The principal element is the Drawing (DRWG), which is the Database equivalent of the traditional paper drawing. All the elements below DRWG in the hierarchy are used to store the information required to completely define the Drawing.

A Drawing can own one or more Sheet (SHEE) elements, which correspond to the sheets of a paper drawing ('Sheet 1 of 3', 'Sheet 2 of 3' etc). A Drawing can consist of a single Sheet. A Sheet is the highest-level element that may be displayed within a view.

A Sheet may own one or more VIEW elements. These are projections of parts of the Design Database. A VIEW element has attributes that:

• define the viewing parameters (looking direction, through point, scale, and so on).

• define the size, position and orientation of the region on the Sheet that the View occupies.

• refer to another Draft database element that contains a list of the Design (or Catalogue) elements that make up the VIEW picture.

The full Draft database hierarchy is illustrated in Draft Database Hierarchy.