Creating Expressions - Dialog Box

Use expressions to do the following tasks:

• Define conditions that retrieve the features you want from a feature source
• Select features for an operation
• Specify criteria for styling or labeling

Expression Elements Menu

Inserts elements into your expression.

Property

Displays a list of properties. Select a property to display its values. For example, for a Building feature with a Street_Address property, you can examine the Street_Address values and choose only buildings on a particular street.

Properties are sometimes called attributes in other GIS systems. Properties can provide demographic, physical, historical, and other data about a geometric feature.

Operator

Displays a list of math, comparison, and logical operators.

Function

Displays a list of Math, Text, Date, Conversion and Geometric functions.

Math Function

Displays a list of math and numeric functions, including standard trigonometric operations, as well as functions for absolute value, exponents, and others.

Text Function

Displays a list of functions that operate on text properties and are useful for formatting the results of text-related queries.

Date Function

Displays a list of functions that return the current date or operate on a date string.

Locate on Map

Specifies a location as a filter when you draw it on your map. For example, select all items within or touching a specified circle, rectangle, or polygon that you draw.

Geometric

Displays the geometric elements Area2D and Length2D. Each of these elements takes only the argument Geometry. Using that argument, the expression determines the area or length of the data on the layer. You can then create an expression that filters data by its size. For example, you can select only pipes longer than 50 feet.

Conversion

Displays a list of options for converting strings from one format to another. For example, you can convert text strings to dates, and then select only items before or after a particular date.

Math operators

Inserts +, -, *, or / into your expression.

Comparison operators

Inserts Boolean comparison operators (equal to, less than, greater than, and so on) into your expression.

Logical operators

Inserts AND, OR, or grouping parentheses into your expression.

Get values

Select a property from the drop-down list in the Values Pane to query available values for that property. Double-click on a value to add that value to your expression at the insertion point.

Expression area

Displays the current expression.

Values Pane

Allows a user to query and use values of selected properties.