MySQL如何获取日期表示去年的今天

用函数date_sub或date_add直接对"年"部分去减就可以了,见下面示例:

mysql>select now()

+---------------------+

| now() |

+---------------------+

| 2010-08-25 09:34:41 |

+---------------------+

1 row in set (0.00 sec)

mysql>select date_add(now(),interval -1 year)

+----------------------------------+

| date_add(now(),interval -1 year) |

+----------------------------------+

| 2009-08-25 09:34:44 |

+----------------------------------+

1 row in set (0.00 sec)

mysql>select date_sub(now(),interval 1 year)

+---------------------------------+

| date_sub(now(),interval 1 year) |

+---------------------------------+

| 2009-08-25 09:34:46 |

+---------------------------------+

1 row in set (0.00 sec)

mysql>

代码如下

    select group_date groupDate from (

    SELECT

    @cdate input_date,

    @last_sat := date_add(date_sub(date_sub(@cdate,interval  day(@cdate)-1 day),interval 1 month), interval 6-date_format(date_sub(date_sub(@cdate,interval  day(@cdate)-1 day),interval 1 month),'%w') day) last_sat,

    @this_sat := date_add(date_sub(@cdate,interval  day(@cdate)-1 day), interval 6-date_format(date_sub(@cdate,interval  day(@cdate)-1 day),'%w') day) this_sat,

    @next_sat := date_add(date_add(date_sub(@cdate,interval  day(@cdate)-1 day),interval 1 month), interval 6-date_format(date_add(date_sub(@cdate,interval  day(@cdate)-1 day),interval 1 month),'%w') day) next_sat,

    @last_point := if(day(@last_sat)-3>0,date_sub(@last_sat,interval 7 day),@last_sat) last_point,

    @this_point := if(day(@this_sat)-3>0,date_sub(@this_sat,interval 7 day),@this_sat) this_point,

    @next_point := if(day(@next_sat)-3>0,date_sub(@next_sat,interval 7 day),@next_sat) next_point ,

    case

    when @cdate >= @last_point and @cdate < @this_point then

    concat(

    'W',

    datediff(@cdate,@last_point) div 7 + 1, '/',

    year(@cdate),'-',

    if(month(@last_sat)>=10,month(@last_sat),concat('0',month(@last_sat)))

    )

    when @cdate >=@this_point and @cdate < @next_point then

    concat(

    'W',

    datediff(@cdate,@this_point) div 7 + 1,'/',

    year(@cdate),'-',

    if(month(@this_sat)>=10,month(@this_sat),concat('0',month(@this_sat))))

    else

    concat(

    'W',

    datediff(@cdate,@next_point) div 7 + 1,'/',

    year(@cdate),'-',if(month(@next_sat)>=10,month(@next_sat),concat('0',month(@next_sat))))

    end

    group_date

    from  (SELECT @cdate := #{inputDate}) as gd

    )；

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