Methods for modifying extraction queries

The extraction queries that are created at the product class level are applied to all products, instances, and areas of interest (AOIs) within them. However, since you can have several different series within a product class, and not all of them may require the same WHERE clauses for extraction, you can modify the WHERE clauses as needed. By modifying the extraction queries for a product, instance, or area of interest, you can refine the queries so they are better suited for the respective component of your chart. You can modify extraction queries from the following product library levels:

• Series
• Product
• Instance
• Area of interest

There are three different methods for modifying a WHERE clause that has been created at the product class level. Below is a table that describes the methods and the results of using them.

Modification method	Description	What it does
OVERRIDE	Allows you to replace the entire WHERE clause, or specific parts, created at the product class level for a specified table or all tables	Part or all of the WHERE clause is replaced so it conforms to the product, instance, or area of interest feature with which you are working. The new clause you create supersedes the clause created at the product class level.
AND	Allows you to append an AND statement to the end of the WHERE clause created at the product class level for a specified table or all tables	The WHERE clause created at the product class level is applied as well as the conditions you add.
OR	Allows you to append an OR statement to the end of the WHERE clause created at the product class level or a specified table or all tables	The WHERE clause created at the product class level is applied as well as the conditions you add.

Query modification method

Reasons for modifying extraction queries at the product, instance, or area of interest level

When you are overriding or appending to an extraction query, you can choose to do so in different levels of your product library. Changing the extraction query at the product level allows you to accommodate differences that can exist between individual map documents within a product class, such as the compilation scale and scale band values.

Extraction queries for instances can be modified when there is more than one for a map document. This allows you to accommodate the different scales that can be used for each instance feature.

With areas of interest, the extraction queries can be modified when there is more than one for a product instance. Depending on the features you are using, there can be differences in the map compilation scales, scale band values, or other attributes.