mysql 分页sql

-- pageSize=3 pageIndex total=7
-- 开始行号 startRowNum=(pageIndex-1)*pageSize+1;
-- 结束行号 endRowNum=pageIndex*pageSize
-- 总页数 (total+pageSize-1)/pageSize



select *  from (
SELECT `code`,cname,@rownum:=@rownum+1 as row_num FROM `dic_town`,(select @rownum:=0) t
)as a where 1=1 and  a.row_num BETWEEN 1 and 3;

select count(*) from `dic_town`;