query: fetch 3 records which has higher value, MySQL

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drop table if exists finaltrade;

CREATE TABLE finaltrade
    (`id` varchar(4), `user_id` varchar(9), `exchange_id` varchar(13), `market_id` varchar(11), `symbol_id` varchar(11), `buy_datetime` varchar(21), `sell_datetime` varchar(21), `buy_rate` int(10), `sell_rate` int(11), `quantities` int(12))
;
    
INSERT INTO finaltrade
    (`id`, `user_id`, `exchange_id`, `market_id`, `symbol_id`, `buy_datetime`, `sell_datetime`, `buy_rate`, `sell_rate`, `quantities`)
VALUES
   
    ('1', '1', '1', '1', '96', '2018-05-25 18:13:26', '0000-00-00 00:00:00', '2205', '0', '100'),
    ('2', '1', '1', '1', '96', '0000-00-00 00:00:00', '2018-05-25 18:13:59', '500', '6680', '100'),
    ('3', '4', '1', '1', '23', '2018-05-25 18:16:27', '0000-00-00 00:00:00', '120', '0', '10'),
    ('4', '1', '1', '1', '96', '2018-05-25 18:13:59', '0000-00-00 00:00:00', '50351', '0', '30'),
    ('5', '1', '1', '1', '15', '0000-00-00 00:00:00', '2018-05-25 18:34:46', '750', '100', '150'),
    ('6', '4', '1', '1', '573', '2018-05-26 09:29:17', '2018-05-27 03:10:09', '107', '10', '10'),
    ('7', '1', '1', '1', '15', '2018-05-11 09:30:54', '2018-05-25 18:34:56', '40', '100', '40')
;

SELECT DISTINCT symbol_id
FROM finaltrade
ORDER BY buy_rate DESC
LIMIT 3;


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