Eddie Awad’s Blog - Latest Comments in Cool SQL function: EXTRACT

Re: Cool SQL function: EXTRACT

Eddie Awad — Thu, 20 Mar 2008 14:30:15 -0000

@Gary: Good idea. Here is an example

select
    extract(hour from cast(sysdate as timestamp)) hh,
    extract(minute from cast(sysdate as timestamp)) mi,
    extract(second from cast(sysdate as timestamp))ss
from dual

Thanks.

Re: Cool SQL function: EXTRACT

Gary Menchen — Wed, 19 Mar 2008 16:41:15 -0000

You can cast a date to a timestamp and then extract the hour.

Re: Cool SQL function: EXTRACT

Glenn — Tue, 18 Sep 2007 22:55:35 -0000

Well, this isn't so useful if you want the name of the day instead of a number. Say, "MON" instead of 2. Back to TO_CHAR!

Re: Cool SQL function: EXTRACT

Rob Vollman — Thu, 29 Dec 2005 14:35:06 -0000

Yes, I just used this the other day. I wrapped it in a DECODE to get a text representation of the month.

Re: Cool SQL function: EXTRACT

Eddie Awad — Wed, 28 Dec 2005 12:57:23 -0000

you cannot extract Hour, minute or second from a date

Yes, the documentation says: The field you are extracting must be a field of the datetime_value_expr or interval_value_expr. For example, you can extract only YEAR, MONTH, and DAY from a DATE value.

I'm not sure exactly why you cannot get to the hour/minute/second from a DATE using EXTRACT, since a DATE datatype contains a time portion as well (but not fractional seconds).

It'll be interesting to know what the reason behind this limitation is.

Re: Cool SQL function: EXTRACT

FranÃ§ois — Wed, 28 Dec 2005 10:12:40 -0000

You can also get this information with the To_Char() function.

SELECT to_char(SYSTIMESTAMP,'FF') FROM dual

Re: Cool SQL function: EXTRACT

Laurent Schneider — Wed, 28 Dec 2005 09:36:36 -0000

interesting is extracting nanoseconds from timestamp :

SQL> create table t as select timestamp '2000-01-01 00:00:42.123456789' t from dual;

Table created.

SQL> select mod(extract(second from t),1)*1000000000 ns from t;
NS

123456789

Re: Cool SQL function: EXTRACT

FranÃ§ois — Wed, 28 Dec 2005 08:36:39 -0000

For an unknown reason you cannot extract Hour, minute or second from a date. It works only on Timestamp.
Francois