Symbology by query, not just quantity

06-20-2013 02:58 PM
Status: Open
Occasional Contributor III
Currently we can use definition queries to form subsets and save them as layers which can be brought into a TOC and grouped as we please.

The downside of that, besides managing separate layer files, is that the records subset is static for any layer file, and if attributes change the records membership in the layer does not reflect that.

Why not make it possible in the symbology tab, under 'Multiple Attributes' to enter query expressions, such as 'NUM_HOUSEHOLDS' > 'AREA_ACRES' or 'ZONING_DISTRICT' <> 'COMMERCIAL' AND 'ELEV' > 500 ?

Thus we could enjoy the combined benefits of queries, categories and quantities all in one dynamic symbology.
I support the idea, but rules would have to be developed when a feature in a single layer meets more than one category expression.  Would it use the lowest or highest symbol in the list?
This would also be useful for symbology based on joined tables.  I have two seperate road condition files, one for 2007, and another for 2011.  Through label expressions I can create a difference, percent change, and etc.  However symbology is limited to normalization to compare one year to the next.