補充1到12月表

 with temps as (select lpad(level, 2, 0) as mon from dual connect by level < 13)
    select decode(t.mon,
	               '01',
	               '一月',
	               '02',
	               '二月',
	               '03',
	               '三月',
	               '04',
	               '四月',
	               '05',
	               '五月',
	               '06',
	               '六月',
	               '07',
	               '七月',
	               '08',
	               '八月',
	               '09',
	               '九月',
	               '10',
	               '十月',
	               '11',
	               '十一月',
	               '12',
	               '十二月') as mon,
	               count(to_char(t1.item_time, 'yyyy-mm')) as num
	   from temps t
	   left join site_c_menu_info t1
	   on t.mon = to_char(t1.item_time, 'mm')
	   and to_char(t1.item_time(+), 'yyyy') = #{year,jdbcType=VARCHAR} 
	  group by t.mon
	  order by t.mon