Exercise 4: Use the joined data for calculated fields and styles

Exercise 3: Join the data from the ODBC source to the layer containing the parcels

Lesson 2: Analyzing Data With External Information Using Joins

Lesson 3: Analyzing Data by Proximity Using Buffers

 

AutoCAD Map 3D Tutorials > Tutorial: Analyzing Data Using Styles, Joins, and Buffers > Lesson 2: Analyzing Data With External Information Using Joins > 

Exercise 4: Use the joined data for calculated fields and styles

Now that you have joined owner data to the parcels layer, you can use the joined information to create a calculated field and determine your styles.

To create a calculated field using joined data

1. At the bottom of the Data Table, click Options, and click Create A Calculation.
2. In the Create A Calculation window, enter a name for the calculated field, for example “AcresByArea.”
3. Click Property to see a list of properties for the current layer. Select ACRES.
4. Click the operator for “divided by” (the slash character).
5. Hover over the [value] marker that is inserted to see a tooltip with choices. Click Enter a Property. Select AREA.
6. Click Validate to make sure the expression is a valid calculation.
7. When you see “The expression is valid,” click OK to create the calculated field.

   Scroll to the right in the Data Table to see the new field (just to the left of the joined fields). It is gray, to indicate that it is a calculated field and cannot be edited. However, you can use it for styling.

You can display information differently at different zoom levels in AutoCAD Map 3D, so you can create a style that displays owner names (from the joined data source) on the parcel layer at a high zoom level, but not at a lower one.

To create a style using the joined data

1. In Display Manager, select the Parcels layer and click Style.
2. Click the button in the field under Feature Label.
3. For Property To Display, select Assessor|OWNERLASTNAME.
4. Click OK.
5. Click Add a Scale Range so that you have two scale ranges, both the same.
6. Set the bounds of the first scale range to 0 to 10000 and the second to 10000 to Infinity.
7. Select the second scale range (10000 to Infinity).
8. Click in the Feature Label field.
9. Clear the check box for Create A Label (at the top of the dialog box) and then click OK.
10. Close the Style Editor.
11. Save your map file.

The new Parcels style will display the owner's name when the view is zoomed to 10000 or closer. The labels are not displayed when you zoom out further than that.