使用GROUP BY和count在结果中优化MySQL查询顺序

Question

I have the following query:

SELECT vBrowser,iconBrowser, count(iconBrowser) as 'N'
FROM user_ip_tmp  WHERE code='9m9g9tsv2y'
GROUP BY iconBrowser
ORDER BY N DESC
LIMIT 40

And this works properly. But the delirious cause query took a long time.

Showing rows 0 - 17 ( 18 total, Query took 4.4189 sec)

Answer 1

Things that are in WHERE statement, should be indexed.

Try to use EXPLAIN statement before your SELECT to see what and how is used to retrief your requested results.

And if the column code is not an unique value, i would recommend to put it in some other table, where it is unique. Then build the query using JOIN though the FOREIGN KEY .