To obtain a random integer R in the range i <= R < j, use the expression FLOOR(i + RAND() * (j – i)). For example, to obtain a random integer in the range the range 7 <= R < 12, you could use the following statement:
SELECT FLOOR(7 + (RAND() * 5));
Related Posts
- January 18, 2012 -- MySQL regex_replace Function
- June 9, 2011 -- 一天总结
- September 13, 2010 -- MySQL锁表机制分析
- September 9, 2010 -- HOWTO: configure MySQL’s my.cnf file
- September 8, 2010 -- MySQL性能优化21 – 使用随机函数产生采样
- September 8, 2010 -- MySQL性能优化20 – ORDER BY 操作的优化
- September 8, 2010 -- MySQL性能优化19 – GROUP BY 操作的优化
- September 8, 2010 -- MySQL性能优化18 – 使用 GROUP BY WITH ROLLUP 改善统计性能
- September 8, 2010 -- MySQL性能优化17 – INSERT操作的优化
- September 8, 2010 -- MySQL性能优化16 – InnoDB 存储引擎
0 Responses to “Range number in MySQL”