Use expressions when you want AutoCAD Map 3D toolset to evaluate drawing data from different sources, or to evaluate data that is different for each object, such as object properties, block attributes, or object data attached to the object.
To define an expression
- In Map Explorer, under Current Drawing, right-click Current Query, and then click Define.
- In the Define Query Of Attached Drawings dialog box, load or create a query.
- Under Options, click Alter Properties.
- In the Set Property Alterations dialog box, select the property to alter.
For example, to change the color of queried objects, select Color.
- In the Expression area, enter an expression.
- Click Add to add the property alteration to the Current Property Alterations list.
- When you finish defining the property alteration, click OK.
- Make sure Alter Properties is selected when you execute the query.
- Under Query Mode, select Draw. You cannot use property alteration in Preview mode or Report mode.
- Click Execute Query.