mysql的5中查询子句之五limit限制查询

limit 在语句最后，起到限制条目的作用。它的语法

limit [offset,]N
offset 偏移量,如果offset不写，默认是0，N
N  取出的条目

1、取出触发器id最高的前三个项目

mysql> select functionid,itemid,triggerid,function from functions order by triggerid desc limit 3;

2、取出触发器id 4,5,6 高的栏目

mysql> select functionid,itemid,triggerid,function from functions order by triggerid desc limit 3,3;

3、取出每个功能里面fuctionid最大的栏目
思路：建立临时表，如果不够建表，需要用到子查询，子查询的结果可以看成一张表

#构建临时表
mysql> select functionid,itemid,triggerid,function from functions order by function,functionid desc;

#用子查询
select * from (select functionid,itemid,triggerid,function from functions order by function,functionid desc) as tmp group by function;

mysql的5中查询子句

mysql的5中查询子句之一where条件查询
http://blog.csdn.net/m0_37886429/article/details/73224579

mysql的5中查询子句之二group by分组查询
http://blog.csdn.net/m0_37886429/article/details/73276996

mysql的5中查询子句之三having条件查询
http://blog.csdn.net/m0_37886429/article/details/73323970

mysql的5中查询子句之四order by排序查询
http://blog.csdn.net/m0_37886429/article/details/73457866

mysql的5中查询子句之五limit限制查询
http://blog.csdn.net/m0_37886429/article/details/73481387