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小编给大家分享一下MySQL使用变量如何实现各种排序,希望大家阅读完这篇文章后大所收获,下面让我们一起去探讨吧!
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--下面我演示下MySQL中的排序列的实现 --测试数据 CREATE TABLE tb ( score INT ); INSERT tb SELECT 5 UNION ALL SELECT 4 UNION ALL SELECT 4 UNION ALL SELECT 4 UNION ALL SELECT 3 UNION ALL SELECT 2 UNION ALL SELECT 1; --1.row_number式的排序 SET @row_number =0; SELECT @row_number := @row_number+1 AS row_number,score FROM tb ORDER BY score DESC ; +------------+-------+ | row_number | score | +------------+-------+ | 1 | 5 | | 2 | 4 | | 3 | 4 | | 4 | 4 | | 5 | 3 | | 6 | 2 | | 7 | 1 | +------------+-------+ --2.dense_rank式的排序 SET @dense_rank = 0,@prev_score = NULL; SELECT @dense_rank :=IF(@prev_score=score,@dense_rank,@dense_rank+1) AS decnse_rank, @prev_score := score AS score FROM tb ORDER BY score DESC ; +-------------+-------+ | decnse_rank | score | +-------------+-------+ | 1 | 5 | | 2 | 4 | | 2 | 4 | | 2 | 4 | | 3 | 3 | | 4 | 2 | | 5 | 1 | +-------------+-------+ --3.rank式的排序 SET @row=0,@rank=0,@prev_score=NULL; SELECT @row:=@row+1 AS ROW, @rank:=IF(@prev_score=score,@rank,@row) AS rank, @prev_score:=score AS score FROM tb ORDER BY score DESC; +------+------+-------+ | ROW | rank | score | +------+------+-------+ | 1 | 1 | 5 | | 2 | 2 | 4 | | 3 | 2 | 4 | | 4 | 2 | 4 | | 5 | 5 | 3 | | 6 | 6 | 2 | | 7 | 7 | 1 | +------+------+-------+
看完了这篇文章,相信你对MySQL使用变量如何实现各种排序有了一定的了解,想了解更多相关知识,欢迎关注创新互联行业资讯频道,感谢各位的阅读!