SQL Sum two values within same query

Question

Good Day,

I have a table that contains 3 columns. Date, Store, Straight_Sales. Each day a new record is created for each store with their previous day's sales.

What I am trying to do is generate a result set that has both current month to date sales for each location as well as the past year same MTD sales.

I can accomplish this by using two totally separate queries and result sets however I am trying to include these in the same query for reporting purposes.

Here are my two current queries that work just fine:

Last Year Month to Date:

     SELECT SUM(summ_sales_daily.straight_sales), store_master.name 
     FROM
     store_master 
     INNER JOIN summ_sales_daily ON store_master.unit = summ_sales_daily.store 
      WHERE YEAR(date)=YEAR(DATE_SUB(NOW(), INTERVAL 1 YEAR)) AND MONTH(date)=MONTH(NOW())
     GROUP BY summ_sales_daily.store ORDER BY summ_sales_daily.store

Current Year Month to Date:

     SELECT SUM(summ_sales_daily.straight_sales), store_master.name 
     FROM
     store_master 
     INNER JOIN summ_sales_daily ON store_master.unit = summ_sales_daily.store 
     WHERE YEAR(date)=YEAR(NOW()) AND MONTH(date)=MONTH(NOW()) 
     GROUP BY summ_sales_daily.store ORDER BY summ_sales_daily.store

I'd like these to return the current and previous years MTD in the same result along with the store name (hence the join)

Any help would be awesome!

Using MariaDB

Answer 1

You can either use conditional aggregation and move the different conditions into a case expression within the sum function:

SELECT 
    store_master.name
    , SUM(CASE WHEN YEAR(date)=YEAR(DATE_SUB(NOW(), INTERVAL 1 YEAR)) THEN summ_sales_daily.straight_sales ELSE 0 END) last_year_sales
    , SUM(CASE WHEN YEAR(date)=YEAR(NOW()) THEN summ_sales_daily.straight_sales ELSE 0 END) current_year_sales
FROM store_master 
INNER JOIN summ_sales_daily ON store_master.unit = summ_sales_daily.store 
WHERE MONTH(date)=MONTH(NOW())
GROUP BY summ_sales_daily.store 
ORDER BY summ_sales_daily.store;

Or you can calculate the two different values in a couple of derived tables that you join with:

SELECT 
  store_master.name, 
  last_year.sales as previous_mtd, 
  current_year.sales as current_mtd
FROM store_master 
LEFT JOIN (
    SELECT store, SUM(straight_sales) sales
    FROM summ_sales_daily
    WHERE YEAR(date)=YEAR(DATE_SUB(NOW(), INTERVAL 1 YEAR)) AND MONTH(date)=MONTH(NOW())
    GROUP BY store 
) last_year ON store_master.unit = last_year.store 
LEFT JOIN (
    SELECT store, SUM(summ_sales_daily.straight_sales) sales
    FROM summ_sales_daily 
    WHERE YEAR(date)=YEAR(NOW()) AND MONTH(date)=MONTH(NOW()) 
    GROUP BY store 
) current_year ON store_master.unit = current_year.store ;

Sample SQL Fiddle

The first solution would probably perform better.