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Oracle ËùÌṩµÄһЩÈÕÆÚº¯ÊýÈçÏÂËùʾ¡£
1. SYSDATE
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SELECT sysdate from dual;
SYSDATE
----------
05-3ÔÂ -03
2. ADD_MONTHS(d, no_of_month)
µ±Ç°ÈÕÆÚ"m"ºóÍÆ"no_of_month"¸öÔ¡£²ÎÊý"no_of_month"¿ÉΪÈκÎÕûÊý¡£
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SELECT add_months(sysdate,2) from dual;
ADD_MONTHS
----------
05-5ÔÂ -03
SELECT add_months(sysdate,-2) from dual;
ADD_MONTHS
----------
05-1ÔÂ -03
3. LAST_DAY(month_day)
·µ»Ø±äÁ¿"month_day"ÖÐËùÖ¸¶¨Ô·ݵÄ×îºóÒ»ÌìµÄÈÕÆÚ¡£
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SELECT last_day(sysdate) from dual;
LAST_DAY(S
----------
31-3ÔÂ -03
4. MONTHS_BETWEEN(d1, d2)
·µ»ØÈÕÆÚ d1 ºÍ d2 Ö®¼äµÄÔ·ÝÊý¡£Èç¹û d1 ÍíÓÚd2£¬½á¹ûΪÕý£¬·ñÔò·µ»Ø¸ºÊý¡£
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SELECT months_between(sysdate,to_date('20030101','YYYYMMDD')) fromdual;
MONTHS_BETWEEN(SYSDATE,TO_DATE('20030101','YYYYMMDD'))
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1¡¢add_months()ÓÃÓÚ´ÓÒ»¸öÈÕÆÚÖµÔö¼Ó»ò¼õÉÙһЩÔ·Ý
date_value:=add_months(date_value,number_of_months)
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SQL> select add_months(sysdate,12) "Next Year" from dual;
Next Year
----------
13-11ÔÂ-04
SQL> select add_months(sysdate,112) "Last Year" from dual;
Last Year
----------
13-3ÔÂ -13
SQL>
2¡¢current_date()·µ»Øµ±Ç°»á·ÅÊ±ÇøÖеĵ±Ç°ÈÕÆÚ
date_value:=current_date
SQL> column sessiontimezone for a15
SQL> select sessiontimezone,current_date from dual;
SESSIONTIMEZONE CURRENT_DA
--------------- ----------
+08:00 13-11ÔÂ-03
SQL> alter session set time_zone='-11:00'
2 /
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SQL> select sessiontimezone,current_timestamp from dual;
SESSIONTIMEZONE CURRENT_TIMESTAMP
--------------- ------------------------------------
-11:00 12-11ÔÂ-0304.59.13.668000 ÏÂÎç -11
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