Oracle古老的中国农历节假日体验（oracle 农历节假日）
Oracle古老的中国农历节假日体验
在中国，农历的重要性不言而喻。许多传统节日如春节、清明节、端午节、中秋节等都是根据农历计算的。Oracle数据库作为一个全球级别的数据库系统，当然也支持农历。不仅仅是支持，Oracle还提供了丰富的日期函数和语言环境，帮助我们快速地处理农历日期，实现各种功能。接下来我们就来学习一下，如何基于Oracle数据库，体验中国古老的农历节假日。
一、建立日期表格
日期表格是日期计算中的核心。建立一个日期表格，可以帮助我们实现很多日期函数和节假日计算。在Oracle数据库中，可以通过CONNECT BY语句和LEVEL行号来生成日期表格。
建立日期表格的代码如下：
CREATE TABLE date_table
(
date_key NUMBER(8) PRIMARY KEY,
date_value DATE,
date_year NUMBER(4),
date_month NUMBER(2),
date_day NUMBER(2),
date_week NUMBER(1),
date_quarter NUMBER(1),
date_half NUMBER(1),
date_season NUMBER(1),
is_weekend NUMBER(1),
is_holiday NUMBER(1),
lunar_year NUMBER(4),
lunar_month NUMBER(2),
lunar_day NUMBER(2),
lunar_zodiac VARCHAR2(4),
lunar_term VARCHAR2(4)
);
INSERT INTO date_table
WITH base AS(
SELECT TO_DATE(‘1900-01-01′,’yyyy-mm-dd’) date_value FROM dual
)
SELECT
TO_NUMBER(TO_CHAR(base.date_value+level-1,’yyyymmdd’)) date_key,
base.date_value+level-1 date_value,
TO_NUMBER(TO_CHAR(base.date_value+level-1,’yyyy’)) date_year,
TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) date_month,
TO_NUMBER(TO_CHAR(base.date_value+level-1,’dd’)) date_day,
TO_NUMBER(TO_CHAR(base.date_value+level-1,’d’)) date_week,
CASE WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (1,2,3) THEN 1
WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (4,5,6) THEN 2
WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (7,8,9) THEN 3
ELSE 4 END date_quarter,
CASE WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (1,2,3,4,5,6) THEN 1
ELSE 2 END date_half,
CASE WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (1,2) OR
TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (11,12) THEN 1
WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (5,6) OR
TO_NUMBER(TO_CHAR(base.date_value+level-1,’mm’)) IN (8,9) THEN 2
ELSE 3 END date_season,
CASE WHEN TO_NUMBER(TO_CHAR(base.date_value+level-1,’d’)) IN (1,7) THEN 1
ELSE 0 END is_weekend,
0 is_holiday,
0 lunar_year,
0 lunar_month,
0 lunar_day,
NULL lunar_zodiac,
NULL lunar_term
FROM base
CONNECT BY LEVEL
二、计算农历日期
计算农历日期是农历节假日体验的关键。在Oracle中，可以借助TO_YMINTERVAL函数和NUMTOYMINTERVAL函数来实现。
代码如下：
CREATE OR REPLACE FUNCTION lunar_date(date_value IN DATE)
RETURN VARCHAR2
IS
lun VARCHAR2(10);
days NUMBER(4);
BEGIN
SELECT FLOOR((date_value-TO_DATE(‘1900-01-31′,’yyyy-mm-dd’))/29.5) INTO days FROM dual;
SELECT
CASE days WHEN 0 THEN ‘正月’ WHEN 1 THEN ‘二月’ WHEN 2 THEN ‘三月’ WHEN 3 THEN ‘四月’
WHEN 4 THEN ‘五月’ WHEN 5 THEN ‘六月’ WHEN 6 THEN ‘七月’ WHEN 7 THEN ‘八月’
WHEN 8 THEN ‘九月’ WHEN 9 THEN ‘十月’ WHEN 10 THEN ‘十一月’ WHEN 11 THEN ‘腊月’
END ||
CASE MOD(CEIL((date_value-TO_DATE(‘1900-01-31′,’yyyy-mm-dd’))/29.5),12) WHEN 0 THEN ‘鼠’
WHEN 1 THEN ‘牛’ WHEN 2 THEN ‘虎’ WHEN 3 THEN ‘兔’ WHEN 4 THEN ‘龙’
WHEN 5 THEN ‘蛇’ WHEN 6 THEN ‘马’ WHEN 7 THEN ‘羊’ WHEN 8 THEN ‘猴’
WHEN 9 THEN ‘鸡’ WHEN 10 THEN ‘狗’ WHEN 11 THEN ‘猪’
END ||
(CASE WHEN MOD(date_value-TO_DATE(‘1900-01-31′,’yyyy-mm-dd’),29.5)>=14 THEN ‘后’ ELSE ‘前’ END)
INTO lun
FROM dual;
RETURN lun;
END;
CREATE OR REPLACE FUNCTION lunar_to_date(lun_y IN NUMBER,lun_m IN NUMBER,lun_d IN NUMBER)
RETURN DATE
IS
lun_days NUMBER(4);
di_days NUMBER(4);
BEGIN
SELECT days INTO lun_days FROM (
SELECT COUNT(*) days FROM date_table WHERE lunar_year=1900 AND lunar_month=1 AND lunar_day=1
);
SELECT days INTO di_days FROM (
SELECT COUNT(*) days FROM date_table WHERE lunar_year=lun_y AND lunar_month=lun_m AND lunar_day=1
);
RETURN (SELECT date_value FROM date_table WHERE date_key=lun_days+di_days+lun_d-1);
END;
UPDATE date_table SET lunar_year = CASE
WHEN date_key
WHEN date_key
…（省略掉800多条代码）
ELSE 1900
END;
UPDATE date_table SET lunar_month = CASE
WHEN date_key IN (731980,732059,732214,732337,732441,732590,732723,732881,733004,733110,733259,733401,733524,733640,733778,733901,734045,734168,734312,734435,734579,734702,734846,734969,735113,735236,735380,735503,735647,735770,735914,736057,736180,736324,736447,736591,736714,736858,736981,737125,737248,737392,737515,737659,737782,737926,738049,738193,738316,738460,738603,738726,738870,739012,739135,739279,739402,739546,739669,739813,739956,740079,740223,740346,740490,740613,740777,741619,741762,741906,742029,742173,742296,742440,742563,742707,742850,742973,743117,743240,743384,743527,743670,743793,743937,744080,744203,744347,744490,744613,744757,744880,745024,745167,745290,745434,745577,745700,745844,745987,746130,746253,746397,746540,746663,746807,746950,747073,747217,747360,747483,747627,747770,747893,748037,748180,748303,748447,748590,748713,748857,749000,749143,749266,749410,749553,749676,749820,749963,750086,750230,750373,750496,750640,750783,750907,751051,751194,751317,751461,751604,751747,751870,752014,752157,752280,752424,752567,752691,752835,752978,753101,753245,753388,753511,753655,753798,753921,754065,754208,754331,754475,754618,754741,754885,755028,755171,755294,755438,755581,755704,755848,755991,756135,756278,756401,
