ruby mysql数据库操作

require 'mysql'
con=Mysql.new('localhost','root','root','test')
con.query('set names utf8')
rs=con.query('select * from demotb')
p rs.num_fields()
p '---------------------'
num=rs.num_rows()
for i in 0..num-1
        rs.data_seek(i)
        a=rs.fetch_row()
        puts a[0]+':'+a[1]
end
p '----------------------'
for i in 0..num-1
        rs.data_seek(i)
        a=rs.fetch_hash()
        puts a['name']+' : '+a['age']
end
rs.free()
con.close
con.close