A link template specifies how to link objects in a drawing to records in a specific database table.
To create a link template
AutoCAD Map 3D uses the value in the key column to uniquely identify a record, so select a column or a combination of columns that contains a unique value for each record in the database.
If the link template does not immediately appear on the Map Explorer tab of the Task Pane, right-click a blank space in Map Explorer. Click Refresh.