1、取url字段後三位字符
1 |
- select SUBSTRING(url, -3) from link;
1 |
- select RIGHT(`url`,length(`url`)-5) from link;
1 |
- select SUBSTRING(url, 3) from link;
1 |
- select SUBSTRING(url, 1, 3) from link;
1 |
- select LEFT(`url`,length(`url`)-5) from link;
1 |
- select SUBSTRING(sDate, 1,7) from forumdata;
二、查詢特定的幾位:
1、正常的模糊查詢
1 |
- select * from cm_order where ordersn like '%31%';
1 |
- select * from cm_order where SUBSTRING(ordersn, 9,2) = 31;
- SELECT * from cm_order where RIGHT(`ordersn`,length(`ordersn`)-8) like '31%';
這種如果正常的模糊查詢會出來很多不相干的數據,但是這種只能針對定長的模糊查詢,效率方面比正常的模糊查詢好很多。