Sum for multiple date ranges in a single call?

Question

I have the following query:

SELECT 
   SUM(\"balance_transactions\".\"fee\") AS sum_id 
   FROM \"balance_transactions\" 
   JOIN charges ON balance_transactions         


        

Answer 1

if i understand well you want to reutilize the date query. For this the part of the query that can be reutilized is the daily part. I mean:

SELECT 
   SUM("balance_transactions"."fee") AS sum_id 
   FROM "balance_transactions" 
   JOIN charges ON balance_transactions.source = charges.balance_id 
   WHERE "balance_transactions"."account_id" = 6 
      AND (balance_transactions.type = 'charge' 
      AND charges.refunded = false 
      AND charges.invoice IS NOT NULL) 
      AND ("balance_transactions"."created" = 'yyyy-mm-dd');

Assuming that your "created" field is just date and not timestamp, and if the data of past days doesn't change, you can dump this query to a table:

insert into sum_table
SELECT 
   "balance_transactions"."created" balance_created
   SUM("balance_transactions"."fee") AS balance_fee 
   FROM "balance_transactions" 
   JOIN charges ON balance_transactions.source = charges.balance_id 
   WHERE "balance_transactions"."account_id" = 6 
      AND (balance_transactions.type = 'charge' 
      AND charges.refunded = false 
      AND charges.invoice IS NOT NULL) 
   group by "balance_transactions"."created"
;

and then change your main query to:

SELECT 
   SUM(balance_fee) AS sum_id 
   FROM sum_table where balance_created between ('2013-12-20' AND '2014-01-19');

Another optimization is to eliminate the between because usually it does not uses indexes, and if you have lots of different dates it can be slow.

Better this way:

SELECT 
   SUM(balance_fee) AS sum_id 
   FROM sum_table where balance_created in ('2013-12-20', '2013-12-21', '2013-12-22' ... '2014-01-19');

But for this you have to create the SQL directly in the client application (ej. DAO)

Hope this helps.