问题:mysql语句中使用like后面的%(百分号) 是不是越多运行效率越慢!
总用时:0.0489秒 0.0691 0.0485 0.0467
SELECT `goods_name`, `goods_img`, `sku_id`, `import` FROM `goods` WHERE `goods_name` LIKE '%iPhone%iPod%' AND `stime` < 1413877244 AND `etime` > 1413877244 ORDER BY `flag` DESC
总用时:0.0460秒 0.0430 0.0493 0.0783 0.0496
SELECT `goods_name`, `goods_img`, `sku_id`, `import` FROM `goods` WHERE `goods_name` LIKE '%iPhone%' AND `goods_name` LIKE '%iPod%' AND `stime` < 1413877367 AND `etime` > 1413877367 ORDER BY `flag` DESC
总用时:0.0458秒 0.0441秒 0.0449秒
SELECT `goods_name`, `goods_img`, `sku_id`, `import` FROM `goods` WHERE `goods_name` LIKE '%%%%%%%%%%%%%%%%%%%%%%%iPhone%iPod%%%%%%%%%%%%%%%%%%%%%%%' AND `stime` < 1413877997 AND `etime` > 1413877997 ORDER BY `flag` DESC
实践证明,百分号的数量不影响sql运行的速度。这几种方法的效率都是差点儿相同的。
以上是我測试的结果。个人可依据自己的实际需求去选择写法!建议是最好选择另外一种!