SQL 打印全年日历

SET @someday := CURDATE();SELECT   MAX(IF(m % 3 = 1       AND row_no = 0, m, '')) AS '月份',  MAX(IF(m % 3 = 1, Sun, '')) AS '日',  MAX(IF(m % 3 = 1, Mon, '')) AS '一',  MAX(IF(m % 3 = 1, Tue, '')) AS '二',  MAX(IF(m % 3 = 1, Wed, '')) AS '三',  MAX(IF(m % 3 = 1, Thur, '')) AS '四',  MAX(IF(m % 3 = 1, Fri, '')) AS '五',  MAX(IF(m % 3 = 1, Sat, '')) AS '六',  MAX(IF(m % 3 = 2       AND row_no = 0, m, '')) AS '月份',  MAX(IF(m % 3 = 2, Sun, '')) AS '日',  MAX(IF(m % 3 = 2, Mon, '')) AS '一',  MAX(IF(m % 3 = 2, Tue, '')) AS '二',  MAX(IF(m % 3 = 2, Wed, '')) AS '三',  MAX(IF(m % 3 = 2, Thur, '')) AS '四',  MAX(IF(m % 3 = 2, Fri, '')) AS '五',  MAX(IF(m % 3 = 2, Sat, '')) AS '六',  MAX(IF(m % 3 = 0       AND row_no = 0, m, '')) AS '月份',  MAX(IF(m % 3 = 0, Sun, '')) AS '日',  MAX(IF(m % 3 = 0, Mon, '')) AS '一',  MAX(IF(m % 3 = 0, Tue, '')) AS '二',  MAX(IF(m % 3 = 0, Wed, '')) AS '三',  MAX(IF(m % 3 = 0, Thur, '')) AS '四',  MAX(IF(m % 3 = 0, Fri, '')) AS '五',  MAX(IF(m % 3 = 0, Sat, '')) AS '六' FROM  (  /* 使用会话变量实现开窗函数的功能，计算每个日期在所在月份里面的相对周 */  SELECT     flag,    m,    wk,    Mon,    Tue,    Wed,    Thur,    Fri,    Sat,    Sun,    @wk_month := IF(m = @month, @wk_month, wk),    wk - @wk_month AS row_no,    @month := m,    @week := wk   FROM    (    /* 把月份当成一个整体，所有的月份的数据都在同一“列”*/    SELECT       flag,      m,      wk,      MAX(IF(wkday = 0, day_index, '')) AS 'Mon',      MAX(IF(wkday = 1, day_index, '')) AS 'Tue',      MAX(IF(wkday = 2, day_index, '')) AS 'Wed',      MAX(IF(wkday = 3, day_index, '')) AS 'Thur',      MAX(IF(wkday = 4, day_index, '')) AS 'Fri',      MAX(IF(wkday = 5, day_index, '')) AS 'Sat',      MAX(IF(wkday = 6, day_index, '')) AS 'Sun'     FROM      (      /* 计算每个日期所在的队、月份、周、星期几*/      SELECT         FLOOR((MONTH(day_m) - 1) / 3) AS flag,        MONTH(day_m) AS m,        WEEK(day_m) AS wk,        WEEKDAY(day_m) AS wkday,        DAY(day_m) AS day_index,        day_m AS full_day       FROM        (        /* 生成一年的日期 */        SELECT           DATE_ADD(first_day, INTERVAL id - 1 DAY) AS day_m         FROM          (          /* 设定年初第一天和年末最后一天的日期 */          SELECT             STR_TO_DATE(              CONCAT(YEAR(@someday), '-01-01'),              '%Y-%m-%d'            ) AS first_day,            STR_TO_DATE(              CONCAT(YEAR(@someday), '-12-31'),              '%Y-%m-%d'            ) AS last_day_year) a,          t_seq t         WHERE t.id <= 1+ DATEDIFF(last_day_year, first_day)) b) c     GROUP BY flag,      m,      wk) d,    (SELECT       @month := 1,      @week := 0,      @wk_month := 0) t   WHERE 1 = 1) e GROUP BY flag,  row_no