SQL oracle中的区间函数
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interval function in oracle
提问by Aaaaa
Query:
询问：
SELECT INTERVAL '300' month,
INTERVAL '54-2' year to month,
INTERVAL ' 11:12:10.1234567' hour to second
FROM DUAL;
The output of the above query is:
上述查询的输出是：
+25-00,+54-02,+00 11:12:10.1234567
Can someone please explain to me how this query is giving this output, with an explanation about the interval function?
有人可以向我解释这个查询是如何给出这个输出的，并解释一下间隔函数吗？
回答by a_horse_with_no_name
INTERVALis not a function it's a keyword that introduces an interval literaland such denotes a data type. Similar to what the literals DATE '2011-05-04'or TIMESTAMP '2011-05-04 17:18:19'are doing.
INTERVAL不是函数，它是一个关键字，它引入了区间文字，表示数据类型。类似于文字DATE '2011-05-04'或TIMESTAMP '2011-05-04 17:18:19'正在做的事情。
Details about interval literals
http://docs.oracle.com/cd/E11882_01/server.112/e41084/sql_elements003.htm#SQLRF00221
http://docs.oracle.com/cd/E11882_01/server.112/e41084/expressions009.htm#SQLRF52084
有关区间文字的详细信息
http://docs.oracle.com/cd/E11882_01/server.112/e41084/sql_elements003.htm#SQLRF00221
http://docs.oracle.com/cd/E11882_01/server.112/e410894/expressions000 .htm#SQLRF52084
Details about the interval datatype:
http://docs.oracle.com/cd/E11882_01/server.112/e41084/sql_elements001.htm#i128552
关于区间数据类型的详细信息：http:
//docs.oracle.com/cd/E11882_01/server.112/e41084/sql_elements001.htm#i128552
回答by Rashmi Rathour
Interval is a function which is used to deduct or add (days,years,months,hour,minutes and seconds) to the given date. interval '300' month : 25-0 Reason : 300/12(months) gives you quotient as 25 and remainder as 0 so the output will be 25-0
间隔是一个函数，用于减去或添加（天、年、月、小时、分钟和秒）到给定的日期。间隔 '300' 月：25-0 原因：300/12(months) 为您提供商为 25，余数为 0，因此输出将为 25-0
interval '54-2' year to month : 54-2 Reason : As you have not mentioned any date it is giving as it is. if you use select sysdate + interval '54-2' year to month from dual; output will be : 1-12-2066
间隔'54-2'年到月：54-2 原因：由于您没有提到任何日期，它按原样给出。如果您使用 select sysdate + interval '54-2' year to month from dual; 输出将是：1-12-2066
sydate : 1-10-2012 so adding 54 to 12 = 66 and adding 2 months to oct which will be dec.
sydate : 1-10-2012 所以将 54 添加到 12 = 66 并将 2 个月添加到 oct，即 12 月。
Same with the last option as well.
与最后一个选项相同。
