Add a SUM field as a data type to perform cross-table tabulation
I chose Caspio over a newer competitor of Caspio because I could have a LITTLE more latitude using Caspio....however, I nearly went with the competitor because they had a SUM field option, that I could set up in a separate table and sum amounts in another table based on criteria determined in my current table.
This functionality is sorely missing. It was the basis of my first support ticket with Caspio. I was told "if you are looking to have a table value updated based on some action or value changed in a different table, this may require a trigger type behavior to be built by our Professional Services team."
That was disheartening....I was expecting this functionality, at the very least a "low-code" alternative...but I haven't seen anything. I've seen people asking for this functionality in the forums, but I've never seen an actual viable solution or workaround.
[Deleted User] commented
Not sure if this helps for your case but you can use Calculated Field in your DataPages to get SUM values in another table with SELECT SQL query. More information can be found at http://howto.caspio.com/datapages/reports/advanced-reporting/calculations-in-forms-and-reports/