Mysql use stored procedure results multiple times within a query

Question

i have a stored procedure in my MySQL db, working fine.

However, since i have to call the same procedure 3 times in the same query with the same parameters, it woulb be a nice performance improvement if i could use the result of the first call instead of subsequent calls.

Edit: changed the example because it was oversimplified, misleading replies

I have to tables: products, and prices - prices change depending on the time of the year, and on payment mode,so structure is: (id, product_id, date_from, date_to, price_mode_1, price_mode_2, price_mode_3)

Example:

what i do now is

SELECT products.*, 
       get_a_quote(products.id,date_to,date_from, quantity_mode_1,quantity_mode_2,quantity_mode_3) 
  FROM peoducts 
 WHERE get_a_quote(products.id,date_to,date_from, quantity_mode_1,quantity_mode_2,quantity_mode_3)  >0 
ORDER BY 
       get_a_quote(products.id,date_to,date_from, quantity_mode_1,quantity_mode_2,quantity_mode_3) 
LIMIT 10

what i want to do is

SELECT products.*, 
       get_a_quote(products.id,date_to,date_from, quantity_mode_1,quantity_mode_2,quantity_mode_3)  into quote
  FROM peoducts 
 WHERE quote  >0 
ORDER BY 
       quote
LIMIT 10

Is this possible?

*Edit: function code *

FUNCTION `get_a_quote`(`productid` INT, `startDate` SMALLINT, `endDate` SMALLINT, `mode_1_quantity` SMALLINT, `mode_2_quantity` TINYINT, `mode_3_quantity` TINYINT) RETURNS smallint(6)
BEGIN
declare totalprice,p_1,p_2,p_3 smallint;
SELECT price_1,price_2,price_3 into p_1,p_2,p_3 FROM pricing WHERE id=productid and ((startDate between date_from and date_to) and (endDate between date_from and date_to));
if p_3 is null then
    set mode_2_quantity=mode_3_quantity+mode_2_quantity;
    set mode_1_quantity=mode_1_quantity+(4*mode_3_quantity);
    set p_3=0;
    set mode_3_quantity=0;
end if;
if p_2 is null then
    set mode_1_quantity=mode_1_quantity+(3*mode_2_quantity);
    set p_2=0;
    set mode_2_quantity=0;
end if;
if mode_1_quantity>0 and p_1 is null then
    return 0;
end if;
set totalprice = p_1*mode_1_quantity+p_2*mode_2_quantity)+p_3*mode_3_quantity);
RETURN totalprice;
END

Thanks everybody

Answer 1

You can do this in a derived table:

SELECT *
FROM (
    SELECT customers.*, 
           totalOrders (customers.id) AS total
      FROM customers
) AS t 
 WHERE total >0 
ORDER BY 
       total 
LIMIT 10

However, I wouldn't use a stored function for this. It's bound to have incredibly bad performance.

I'd use a JOIN so that I only fetch customers who have more than zero orders.

Answer 2

To me it semantically looks like you are adding a new, dependent column on the table. For which you could use a view:

CREATE VIEW v AS
SELECT customers.*, 
   get_a_quote(products.id,date_to,date_from, quantity_mode_1,quantity_mode_2,quantity_mode_3) AS total
FROM customers;

Then you can simply use it in your query:

SELECT *
FROM v
WHERE total >0 
ORDER BY 
    total 
LIMIT 10;

But then again what your function is doing might be better implemented using a JOIN on your tables, something like:

SELECT customers.*, 
       SUM(orders.value) 
FROM
    customers
    JOIN orders ON
         customers.id=orders.customer_id 
GROUP BY customers.id
HAVING SUM(orders.value)  >0 
ORDER BY 
    SUM(orders.value) 
LIMIT 10;

can you show us your function code?