关于oracle与php时间转换函数

CREATE OR REPLACE FUNCTION date_to_unixts(oracle_date IN DATE) RETURN PLS_INTEGER IS
/**
* Converts an Oracle DATE to a UNIX timestamp
*/
unix_epoch DATE := TO_DATE('19700101080000','YYYYMMDDHH24MISS');
max_date DATE := TO_DATE('20380101000000','YYYYMMDDHH24MISS');
min_date DATE := TO_DATE('19030101000000','YYYYMMDDHH24MISS');
unix_ts PLS_INTEGER;

BEGIN

IF oracle_date > max_date THEN
RAISE_APPLICATION_ERROR( -20902,'Date too large for 32bit UNIX timestamp' );
ELSIF oracle_date < min_date THEN
RAISE_APPLICATION_ERROR( -20902,'Date too small for 32bit UNIX timestamp' );
ELSE
unix_ts := (oracle_date - unix_epoch) / (1/86400);
END IF;

RETURN (unix_ts);

END;

CREATE OR REPLACE FUNCTION unixts_to_date(unixts IN PLS_INTEGER) RETURN DATE IS
/**
* Converts a UNIX timestamp into an Oracle DATE
*/
unix_epoch DATE := TO_DATE('19700101080000','YYYYMMDDHH24MISS');
max_ts PLS_INTEGER := 2145916799; -- 2938-12-31 23:59:59
min_ts PLS_INTEGER := -2114380800; -- 1903-01-01 00:00:00
oracle_date DATE;

BEGIN

IF unixts > max_ts THEN
RAISE_APPLICATION_ERROR(
-20901,
'UNIX timestamp too large for 32 bit limit'
);
ELSIF unixts < min_ts THEN
RAISE_APPLICATION_ERROR(
-20901,
'UNIX timestamp too small for 32 bit limit' );
ELSE
oracle_date := unix_epoch + NUMTODSINTERVAL(unixts, 'SECOND');
END IF;

RETURN (oracle_date);

END;