DROP TABLE IF EXISTS ProductZeroPurchasesByProvince;

CREATE TABLE ProductZeroPurchasesByProvince AS 
SELECT 
    c.name AS CountryName, 
    pro.name AS ProvinceName, 
    COUNT(pro.name) AS cnt
FROM 
    Purchases pur
JOIN 
    Province pro ON pur.product = 0 AND pur.province = pro.rowid 
JOIN 
    Country c ON pro.country = c.code
GROUP BY 
    c.code, pro.name;

DROP INDEX IF EXISTS Time_index;
CREATE INDEX Time_index ON Purchases(time,province,product,qty);
