Background: Thing/Node/Sequence/Element, System Data, Names
Related: Hierarchy, Tree, Grid, ComboBox, How to Change an Attribute Value

DBD's tree, grid and drop-down lists provide a limited/partial/filtered view of things in the database. The grid is efficient at displaying a group of things with similar attributes. The tree is efficient at displaying things with varied attributes and hierarchies.

In the figure, both tree and grid display the same things: john and mary. But note that, while john has two professions, only the first one is displayed in the grid. And because mary has no profession, the related grid cell is empty. Also note that while the grid, which represents each person with a row, displays their ID and name attributes; the tree, which represents each person with a node, does not display a thing's ID or the attribute name as a separate node, but instead displays their name in the node's label. The node for the attribute name is hidden by default.

The terms table, record, class, instances, etc indicates a thing in relationship to other things. A single thing can be a class, instance, attribute, value, part, parent, etc relative to different things.

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