I have this query: Find the branch and branche's city with the biggest avg amounts for product 'beta600' between 2010-2014.
I execute this code but I get no results. It takes about 10 min to execute and it gives null. Can u help?
SELECT DISTINCT branch_code,branch_city, AVG(trn_amount)) AS max_avg
WHERE branches.branch_code = accounts.branch_code AND
products.product_code = accounts.product_code AND
accounts.account_id = transactions.account_id AND
product_name = 'Beta600' AND
trn_date > '31/12/2009' AND trn_date < '1/1/2015'
GROUP BY branch_code,branch_city
ORDER BY max_avg
Your approach seems reasonable, but the query could use some work. Here are recommendations:
JOINsyntax. Simple rule: Never use commas in the
use explicitJOIN` syntax.
The resulting query:
SELECT b.branch_code, b.branch_city, AVG(t.trn_amount)) AS max_avg FROM branches b JOIN accounts a ON b.branch_code = a.branch_code JOIN transactions t ON a.account_id = t.account_id JOIN products p ON p.product_code = a.product_code WHERE p.product_name = 'beta600' AND t.trn_date > '2009-12-31' AND t.trn_date < '2015-01-01' GROUP BY branch_code, branch_city ORDER BY max_avg LIMIT 1;
If your query is returning no results, then the
WHERE clause is filtering everything out. Perhaps the date format or casing of the product name is causing the problem.