On May 7, 4:45=A0pm, "fitzjarr...@[EMAIL PROTECTED]
" <orat...@[EMAIL PROTECTED]
> wrote:
> On May 7, 3:08=A0pm, Mark D Powell <Mark.Pow...@[EMAIL PROTECTED]
> wrote:
>
>
>
> > On May 7, 3:52=A0pm, "fitzjarr...@[EMAIL PROTECTED]
" <orat...@[EMAIL PROTECTED]
> wrote:
>
> > > On May 7, 12:51=A0pm, sybra...@[EMAIL PROTECTED]
wrote:
>
> > > > On Wed, 7 May 2008 18:45:04 +0200, "buu" <a...@[EMAIL PROTECTED]
> wrote:
> > > > >question is simple... I have an date field in an table and I
would =
like to
> > > > >measure time difference (minutes or sec.) between current time
and =
that
> > > > >field.
>
> > > > >at wich way you propose?
>
> > > > Assuming a non-paleolithic version of Oracle (I appreciate, you,
as
> > > > someone asking help, can't be bothered to post it, as you assume
> > > > Oracle never changes), one would just subtract the two dates (the
un=
it
> > > > of a date is a day), so you get the difference expressed as a days
> > > > fraction and feed that through the numtodsinterval function.
>
> > > > --
> > > > Sybrand Bakker
> > > > Senior Oracle DBA
>
> > > With many thanks to William Robertson for sharing this on his Oracle
> > > WTF site.
>
> > > <sarcasm>
> > > Oh, but it's much more fun to make things complicated:
>
> > > SQL> --
> > > SQL> -- Let's build a package of convoluted
> > > SQL> -- mathematical il-logic to return what
> > > SQL> -- would normally be the result of a
> > > SQL> -- simple subtraction of dates
> > > SQL> --
> > > SQL> --
> > > SQL> -- You simply can't beat complexity
> > > SQL> --
> > > SQL> -- Many thanks to William Robertson
> > > SQL> -- for bringing this exquisite example
> > > SQL> -- to my attention and for providing
> > > SQL> -- the table population code
> > > SQL> --
> > > SQL>
> > > SQL> CREATE PACKAGE dates_pkg
> > > =A0 2 =A0AS
> > > =A0 3 =A0 =A0 =A0FUNCTION julian_date
> > > =A0 4 =A0 =A0 =A0 =A0 =A0( date_to_convert DATE )
> > > =A0 5 =A0 =A0 =A0 =A0 =A0RETURN NUMBER;
> > > =A0 6
> > > =A0 7 =A0 =A0 =A0FUNCTION minutes_since_midnight
> > > =A0 8 =A0 =A0 =A0 =A0 =A0( timevalue DATE )
> > > =A0 9 =A0 =A0 =A0 =A0 =A0RETURN NUMBER;
> > > =A010
> > > =A011 =A0 =A0 =A0FUNCTION minutes_elapsed
> > > =A012 =A0 =A0 =A0 =A0 =A0( lowdate DATE
> > > =A013 =A0 =A0 =A0 =A0 =A0, highdate DATE )
> > > =A014 =A0 =A0 =A0 =A0 =A0RETURN NUMBER;
> > > =A015
> > > =A016 =A0END dates_pkg;
> > > =A017 =A0/
>
> > > Package created.
>
> > > Elapsed: 00:00:00.01
> > > SQL>
> > > SQL> CREATE PACKAGE BODY dates_pkg
> > > =A0 2 =A0AS
> > > =A0 3 =A0 =A0 =A0FUNCTION julian_date
> > > =A0 4 =A0 =A0 =A0 =A0 =A0( date_to_convert DATE)
> > > =A0 5 =A0 =A0 =A0 =A0 =A0RETURN NUMBER
> > > =A0 6 =A0 =A0 =A0IS
> > > =A0 7 =A0 =A0 =A0 =A0 =A0varch_value VARCHAR (10);
> > > =A0 8 =A0 =A0 =A0 =A0 =A0num_value NUMBER (20);
> > > =A0 9 =A0 =A0 =A0BEGIN
> > > =A010 =A0 =A0 =A0 =A0 =A0--
> > > =A011 =A0 =A0 =A0 =A0 =A0-- First, we take a date and convert it to
a =
date by
> > > converting it
> > > =A012 =A0 =A0 =A0 =A0 =A0-- to a character string using the same
forma=
t we will use
> > > to
> > > =A013 =A0 =A0 =A0 =A0 =A0-- convert it BACK to a date again
> > > =A014 =A0 =A0 =A0 =A0 =A0--
> > > =A015 =A0 =A0 =A0 =A0 =A0-- Oh, then we convert it back to a
character=
string
> > > =A016 =A0 =A0 =A0 =A0 =A0--
> > > =A017 =A0 =A0 =A0 =A0 =A0-- In Julian format, which is a number
> > > =A018 =A0 =A0 =A0 =A0 =A0--
> > > =A019 =A0 =A0 =A0 =A0 =A0SELECT TO_CHAR
> > > =A020 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 (
TO_DATE(TO_CHAR(date_to_conver=
t,'MM/DD/YYYY'),'MM/DD/
> > > YYYY')
> > > =A021 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 , 'J')
> > > =A022 =A0 =A0 =A0 =A0 =A0INTO =A0 varch_value
> > > =A023 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > =A024
> > > =A025 =A0 =A0 =A0 =A0 =A0--
> > > =A026 =A0 =A0 =A0 =A0 =A0-- Okay, so we had a Julian date as a
number =
but we changed
> > > it to
> > > =A027 =A0 =A0 =A0 =A0 =A0-- a character string so we could go back
and=
make it a ...
> > > =A028 =A0 =A0 =A0 =A0 =A0-- NUMBER ... again
> > > =A029 =A0 =A0 =A0 =A0 =A0--
> > > =A030 =A0 =A0 =A0 =A0 =A0SELECT TO_NUMBER (varch_value)
> > > =A031 =A0 =A0 =A0 =A0 =A0INTO =A0 num_value
> > > =A032 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > =A033
> > > =A034 =A0 =A0 =A0 =A0 =A0--
> > > =A035 =A0 =A0 =A0 =A0 =A0-- So, we finally make up our mind and keep
i=
t a number and
> > > =A036 =A0 =A0 =A0 =A0 =A0-- return it from the function
> > > =A037 =A0 =A0 =A0 =A0 =A0--
> > > =A038 =A0 =A0 =A0 =A0 =A0RETURN (num_value);
> > > =A039 =A0 =A0 =A0END julian_date;
> > > =A040
> > > =A041
> > > =A042 =A0 =A0 =A0FUNCTION minutes_since_midnight (
> > > =A043 =A0 =A0 =A0 =A0 =A0timevalue DATE)
> > > =A044 =A0 =A0 =A0 =A0 =A0RETURN NUMBER
> > > =A045 =A0 =A0 =A0IS
> > > =A046 =A0 =A0 =A0 =A0 =A0secs_elapsed NUMBER (20);
> > > =A047 =A0 =A0 =A0 =A0 =A0mins_elapsed NUMBER (20);
> > > =A048 =A0 =A0 =A0BEGIN
> > > =A049 =A0 =A0 =A0 =A0 =A0--
> > > =A050 =A0 =A0 =A0 =A0 =A0-- So now we take a date and extract the
time=
****tion of
> > > it,
> > > =A051 =A0 =A0 =A0 =A0 =A0-- convert that BACK to a date, then
convert =
THAT to a
> > > string
> > > =A052 =A0 =A0 =A0 =A0 =A0-- of seconds and convert THAT to a number
> > > =A053 =A0 =A0 =A0 =A0 =A0--
> > > =A054 =A0 =A0 =A0 =A0 =A0-- Is it me, or are we essentially driving
ac=
ross town just
> > > to
> > > =A055 =A0 =A0 =A0 =A0 =A0-- go next door?
> > > =A056 =A0 =A0 =A0 =A0 =A0--
> > > =A057 =A0 =A0 =A0 =A0 =A0SELECT TO_NUMBER
> > > =A058 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 (
TO_CHAR(TO_DATE(TO_CHAR(timeva=
lue,'HH:MI AM'),'HH:MI AM')
> > > =A059 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 , 'SSSSS') )
> > > =A060 =A0 =A0 =A0 =A0 =A0INTO =A0 secs_elapsed
> > > =A061 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > =A062
> > > =A063 =A0 =A0 =A0 =A0 =A0--
> > > =A064 =A0 =A0 =A0 =A0 =A0-- Oooo, now we divide that total number of
s=
econds by ...
> > > =A065 =A0 =A0 =A0 =A0 =A0-- wait for it ...
> > > =A066 =A0 =A0 =A0 =A0 =A0-- any second now ...
> > > =A067 =A0 =A0 =A0 =A0 =A0-- 60! =A0Who would have thought that 60
seco=
nds equals
> > > =A068 =A0 =A0 =A0 =A0 =A0-- one minute?
> > > =A069 =A0 =A0 =A0 =A0 =A0--
> > > =A070 =A0 =A0 =A0 =A0 =A0SELECT (secs_elapsed / 60)
> > > =A071 =A0 =A0 =A0 =A0 =A0INTO =A0 mins_elapsed
> > > =A072 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > =A073
> > > =A074 =A0 =A0 =A0 =A0 =A0--
> > > =A075 =A0 =A0 =A0 =A0 =A0-- Before we rest on our laurels we return
th=
e minutes
> > > since midnight
> > > =A076 =A0 =A0 =A0 =A0 =A0--
> > > =A077 =A0 =A0 =A0 =A0 =A0RETURN (mins_elapsed);
> > > =A078 =A0 =A0 =A0END minutes_since_midnight;
> > > =A079
> > > =A080
> > > =A081 =A0 =A0 =A0FUNCTION minutes_elapsed
> > > =A082 =A0 =A0 =A0 =A0 =A0( lowdate DATE
> > > =A083 =A0 =A0 =A0 =A0 =A0, highdate DATE )
> > > =A084 =A0 =A0 =A0 =A0 =A0RETURN NUMBER
> > > =A085 =A0 =A0 =A0IS
> > > =A086 =A0 =A0 =A0 =A0 =A0final_number NUMBER (20);
> > > =A087 =A0 =A0 =A0 =A0 =A0low_julian NUMBER (20);
> > > =A088 =A0 =A0 =A0 =A0 =A0high_julian NUMBER (20);
> > > =A089 =A0 =A0 =A0 =A0 =A0num_days NUMBER (20);
> > > =A090 =A0 =A0 =A0 =A0 =A0num_minutes NUMBER (20);
> > > =A091 =A0 =A0 =A0 =A0 =A0temp_mins NUMBER (20);
> > > =A092 =A0 =A0 =A0 =A0 =A0min_low NUMBER (20);
> > > =A093 =A0 =A0 =A0 =A0 =A0min_high NUMBER (20);
> > > =A094 =A0 =A0 =A0BEGIN
> > > =A095 =A0 =A0 =A0 =A0 =A0--
> > > =A096 =A0 =A0 =A0 =A0 =A0-- Now, why didn't we use this julian_date
fu=
nction in the
> > > =A097 =A0 =A0 =A0 =A0 =A0-- last installment of Julian conversions?
> > > =A098 =A0 =A0 =A0 =A0 =A0--
> > > =A099 =A0 =A0 =A0 =A0 =A0-- Oh, yeah, because we just WROTE that
wonde=
rful function
> > > 100 =A0 =A0 =A0 =A0 =A0--
> > > 101 =A0 =A0 =A0 =A0 =A0-- So, okay, we take our date values and
return=
the Julian
> > > 102 =A0 =A0 =A0 =A0 =A0-- representations of them using all of the
mat=
hematical
> > > 103 =A0 =A0 =A0 =A0 =A0-- aerobics from earlier
> > > 104 =A0 =A0 =A0 =A0 =A0--
> > > 105 =A0 =A0 =A0 =A0 =A0-- I guess this is so much easier than simply
s=
ubtracting
> > > 106 =A0 =A0 =A0 =A0 =A0-- them
> > > 107 =A0 =A0 =A0 =A0 =A0--
> > > 108 =A0 =A0 =A0 =A0 =A0SELECT julian_date (lowdate)
> > > 109 =A0 =A0 =A0 =A0 =A0INTO =A0 low_julian
> > > 110 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 111
> > > 112 =A0 =A0 =A0 =A0 =A0SELECT julian_date (highdate)
> > > 113 =A0 =A0 =A0 =A0 =A0INTO =A0 high_julian
> > > 114 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 115
> > > 116 =A0 =A0 =A0 =A0 =A0--
> > > 117 =A0 =A0 =A0 =A0 =A0-- Woo-hoo! Higher math time! =A0Subtract the
J=
ulian dates
> > > 118 =A0 =A0 =A0 =A0 =A0-- and get the number of days
> > > 119 =A0 =A0 =A0 =A0 =A0--
> > > 120 =A0 =A0 =A0 =A0 =A0-- Isn't that what we'd get if we just
subtract=
ed the
> > > 121 =A0 =A0 =A0 =A0 =A0-- submitted dates as-is?
> > > 122 =A0 =A0 =A0 =A0 =A0--
> > > 123 =A0 =A0 =A0 =A0 =A0-- Of course it is
> > > 124 =A0 =A0 =A0 =A0 =A0--
> > > 125 =A0 =A0 =A0 =A0 =A0SELECT (high_julian - low_julian)
> > > 126 =A0 =A0 =A0 =A0 =A0INTO =A0 num_days
> > > 127 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 128
> > > 129 =A0 =A0 =A0 =A0 =A0--
> > > 130 =A0 =A0 =A0 =A0 =A0-- Now we calculate the total minutes elapsed
> > > 131 =A0 =A0 =A0 =A0 =A0-- using our values generated by our extreme
> > > 132 =A0 =A0 =A0 =A0 =A0-- gyrations
> > > 133 =A0 =A0 =A0 =A0 =A0--
> > > 134 =A0 =A0 =A0 =A0 =A0-- I'm out of breath just thinking about all
of=
this work
> > > 135 =A0 =A0 =A0 =A0 =A0--
> > > 136 =A0 =A0 =A0 =A0 =A0SELECT (num_days * 1440)
> > > 137 =A0 =A0 =A0 =A0 =A0INTO =A0 num_minutes
> > > 138 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 139
> > > 140 =A0 =A0 =A0 =A0 =A0--
> > > 141 =A0 =A0 =A0 =A0 =A0-- And now we put those other mathematical
move=
s
> > > 142 =A0 =A0 =A0 =A0 =A0-- to use
> > > 143 =A0 =A0 =A0 =A0 =A0--
> > > 144 =A0 =A0 =A0 =A0 =A0-- Tell me again why we think we're smarter
tha=
n
> > > 145 =A0 =A0 =A0 =A0 =A0-- the average bear?
> > > 146 =A0 =A0 =A0 =A0 =A0--
> > > 147 =A0 =A0 =A0 =A0 =A0SELECT minutes_since_midnight (lowdate)
> > > 148 =A0 =A0 =A0 =A0 =A0INTO =A0 min_low
> > > 149 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 150
> > > 151 =A0 =A0 =A0 =A0 =A0SELECT minutes_since_midnight (highdate)
> > > 152 =A0 =A0 =A0 =A0 =A0INTO =A0 min_high
> > > 153 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 154
> > > 155 =A0 =A0 =A0 =A0 =A0--
> > > 156 =A0 =A0 =A0 =A0 =A0-- Now this is disgusting
> > > 157 =A0 =A0 =A0 =A0 =A0--
> > > 158 =A0 =A0 =A0 =A0 =A0-- Using a TEMP variable to aid in simple
mathe=
matical
> > > 159 =A0 =A0 =A0 =A0 =A0-- processing
> > > 160 =A0 =A0 =A0 =A0 =A0--
> > > 161 =A0 =A0 =A0 =A0 =A0SELECT (min_high - min_low)
> > > 162 =A0 =A0 =A0 =A0 =A0INTO =A0 temp_mins
> > > 163 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 164
> > > 165 =A0 =A0 =A0 =A0 =A0--
> > > 166 =A0 =A0 =A0 =A0 =A0-- And this is better than:
> > > 167 =A0 =A0 =A0 =A0 =A0-- select (end_date - start_date)*1440
because?=
> > > 168 =A0 =A0 =A0 =A0 =A0--
> > > 169 =A0 =A0 =A0 =A0 =A0SELECT (num_minutes + temp_mins)
> > > 170 =A0 =A0 =A0 =A0 =A0INTO =A0 final_number
> > > 171 =A0 =A0 =A0 =A0 =A0FROM =A0 dual;
> > > 172
> > > 173 =A0 =A0 =A0 =A0 =A0RETURN (final_number);
> > > 174
> > > 175 =A0 =A0 =A0END minutes_elapsed;
> > > 176 =A0END dates_pkg;
> > > 177 =A0/
>
> > > Package body created.
>
> > > Elapsed: 00:00:00.04
> > > SQL>
> > > SQL> --
> > > SQL> -- This is more fun with a test table
> > > SQL> --
> > > SQL>
> > > SQL> create table date_tst ( start_dt date, end_dt date);
>
> > > Table created.
>
> > > Elapsed: 00:00:00.01
> > > SQL>
> > > SQL> insert into date_tst
> > > =A0 2 =A0select date '2006-12-25' + dbms_random.value(1,365)
> > > =A0 3 =A0 =A0 =A0 , date '2007-12-25' + dbms_random.value(1,365)
> > > =A0 4 =A0FROM =A0 dual connect by level <=3D 4000;
>
> > > 4000 rows created.
>
> ...
>
> read more =BB- Hide quoted text -
>
> - Show quoted text -
I was thinking timestamp because of the subject line. It is probably
just a saved date so only simple date math is required though I alwyas
have a heck of a time constructing simple date math when you want
hours, minutes, seconds broken out. Eventually I get the mods,
commas, and parenthesis correct.
-- Mark D Powell --
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