To create an expression
For example, in the AutoCAD Map 3D toolset Display Manager, right-click the layer, and click Query To Filter Data. The layer you right-clicked is the data source for the expression. When you filter the data, AutoCAD Map 3D toolset displays only the data in that layer that matches the conditions of the expression.
If the expression startup page is turned on, buttons representing different expression types are displayed. You can click one of these buttons to insert an expression template.
Click one of these buttons to start with a sample expression.
To prevent these startup buttons from displaying each time you create an expression, select the Don’t Show At Startup check box. You can redisplay them later by clicking Getting Started.
To close the startup page, click Close.
Click an element to see a menu of options for replacing or deleting it.
Use the menus and buttons at the top of the window to insert elements.
All expressions consist of text you can type.
An expression can combine operations in many ways. For example, you can calculate the area of all parcels and then find features that have the StreetName “Elm” and are larger than 20,000 square feet.
ST_NAME = 'ELM St'
Area2D (Geometry) < 12000
The Geometry property may have a different name in your data store. It is always listed under Geometry Properties in the Property list. Insert the property from the list. Do not change it manually or substitute a value for this property.
ToDate (PURCHASE_DATE, MM/DD/YYYY) AND PURCHASE_DATE < 01/01/2005
Concat (ST_NAME, ‘ ‘, SUFFIX)
Ceil (REPAIR_COST)
For help with any expression element, see Creating Expressions - Reference.
Validation checks the syntax of the expression only. It does not check whether the values you specified are valid for the data, or whether the results are as expected. If there are validation problems, an error message helps direct you to their solutions.