I have data that lists foreclosures by APN. Because of condominiums, apartments, etc., multiple APN records can link to ONE physical parcel. So there is a 1:Many relation between my parcels and my APN records. Is there a way I can display selected attributes from the APN records as tooltip for parcels? I would like to have a tool tip that shows selected/related APN attributes as I hover over my parcels.
If you are only interested in seeing a few attributes from the APN table then we might get away with a simple Aggregation of the detail feature class APN table to the input summary Parcel table. The relation between the summary Parcel table and the detail APN table could be based on common attributes such as the APN (see Attributes tab in Aggregation). When summarizing detail features to the summary feature you would have to use the Output tab to summarize the detail features to one value that is assigned to one or more summary features. This summarization process commonly uses functions such as FIRST, SUM, MIN, AVG etc..
So as an example, if your APN table contained a Tax_Value then the output function could be created to get the average Tax_Value for each parcel using a function such as:
In your case we need to list a set of attributes so we can use the CONCATENATE function. The CONCATENATE function allows you to build a value separated list of detail text attributes. If an attribute is not of type text then we would first have to use the CAST function to change/cast the attribute as a text data type.
Now back to our CONCATENATE Function:
CONCATENATE(Separator, String, Orderby)
Where the Orderby is optional.
We need a list of Owner names seperated by a semi-colon sorted by the Tax_Value
We need to a list of Tax_Values seperated by comma. In this case we have to resort to our CAST function.
If you wanted to sort them by the value then it might look like:
Now if instead of a comma separator we inserted a line break as a delimiter then we could use the resulting attribute as Map View Tool tip or as input to Insert Label to create a nice list for each parcel.
If we wanted a list of owners ordered by tax value, the NEWLINE constant can be used to break out a new line. So if we sub in the NEWLINE our example might look like:
For example if you wanted to have the APN attributes of APN number, owner, and tax value with a double space then the syntax could be modified to:
CONCATENATE(NEWLINE,Detail.APN+" "+Detail.Owner_Name+" "+Detail.Tax_Value,Detail.Tax_Value)
The resulting functional attribute could be used as a tool tip for the map legend entry OR you could use it for labeling.
There are other options such as the statistical LOOKUP function which can be very useful. LOOKUP allows you to pick off one attribute based on locating a value in a different column. LOOKUP can be used as part of Aggregation on the detail feature or in Analytical Merge. Since it’s an aggregating function there is limited use for LOOKUP in the Functional Attributes command.
LOOKUP(what, where, result)
For example for each set of APN records to be associated with a parcel in aggregation, find the MAX(detail.Tax_Value) and then lookup the owner name.
LOOKUP(MAX(Detail.Tax_Rate), Detail.Tax_Rate, Detail.Owner_Name)