[SQL] Simple Question
Hello: I'm trying to figure out how to convert a floating point value into an interval of time. I'm calculating the time required to drive from point A to point B. For the sake of this question, we'll just say it is miles/speed. So: drv_time = 478 / 45.0; The value of this is: 10.6222 Is there a way of converting this value to an interval. It seems that INTERVAL only works with a quoted literal value. If I type: rnd=# select interval '10.8444 hours'; interval @ 10 hours 50 mins 40 secs (1 row) Anybody have an pointers? Thanks... Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [SQL] Simple Question
I figured it out. This works: travel_window INTERVAL; drv_time FLOAT; drv_time = miles / 45.0;-- drive time travel_window = quote_literal(drv_time || '' hours''); The variable, travel_window becomes: @ 10 hours 50 mins 40 secs, which is what I wanted. If anybody knows any other ways, I'd be interested in see that too. On Tuesday 11 January 2005 04:42 pm, Terry Lee Tucker saith: Hello: I'm trying to figure out how to convert a floating point value into an interval of time. I'm calculating the time required to drive from point A to point B. For the sake of this question, we'll just say it is miles/speed. So: drv_time = 478 / 45.0; The value of this is: 10.6222 Is there a way of converting this value to an interval. It seems that INTERVAL only works with a quoted literal value. If I type: rnd=# select interval '10.8444 hours'; interval @ 10 hours 50 mins 40 secs (1 row) Anybody have an pointers? Thanks... Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [SQL] Simple Question
On Tue, Jan 11, 2005 at 04:42:21PM -0500, Terry Lee Tucker wrote: Subject: [SQL] Simple Question Please use a more descriptive subject -- think about how somebody looking at a list of 200 messages, all with subjects like Simple Question or PostgreSQL Question, would decide to look at yours. drv_time = 478 / 45.0; The value of this is: 10.6222 Is there a way of converting this value to an interval. It seems that INTERVAL only works with a quoted literal value. You can do arithmetic on intervals: SELECT 478 / 45.0 * interval'1 hour'; For more information, see Date/Time Functions and Operators in the documentation. -- Michael Fuhr http://www.fuhr.org/~mfuhr/ ---(end of broadcast)--- TIP 8: explain analyze is your friend
Re: [SQL] Simple Question
Convert to seconds first (3600 sec/hr) : select ( '3600'::int4 * '478'::int4 / '45.0'::float8 )::int4::reltime::interval ; interval -- 10:37:20 (1 row) I don't know if ::int4::reltime::interval is the best way to end up with an interval, but its the only way I could figure out how to do it off the top of my head. On Tue, 2005-11-01 at 16:42 -0500, Terry Lee Tucker wrote: Hello: I'm trying to figure out how to convert a floating point value into an interval of time. I'm calculating the time required to drive from point A to point B. For the sake of this question, we'll just say it is miles/speed. So: drv_time = 478 / 45.0; The value of this is: 10.6222 Is there a way of converting this value to an interval. It seems that INTERVAL only works with a quoted literal value. If I type: rnd=# select interval '10.8444 hours'; interval @ 10 hours 50 mins 40 secs (1 row) Anybody have an pointers? Thanks... Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster -- Guy Fraser Network Administrator The Internet Centre 1-888-450-6787 (780)450-6787 ---(end of broadcast)--- TIP 8: explain analyze is your friend
Re: [SQL] Simple Question
On Tue, 11 Jan 2005, Terry Lee Tucker wrote: Hello: I'm trying to figure out how to convert a floating point value into an interval of time. I'm calculating the time required to drive from point A to point B. For the sake of this question, we'll just say it is miles/speed. So: drv_time = 478 / 45.0; The value of this is: 10.6222 I think something like 478/45.0 * interval '1 hour' may do what you want. ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [SQL] Simple Question
Thank you for the reply in spite of the subject. On Tuesday 11 January 2005 05:15 pm, Michael Fuhr saith: On Tue, Jan 11, 2005 at 04:42:21PM -0500, Terry Lee Tucker wrote: Subject: [SQL] Simple Question Please use a more descriptive subject -- think about how somebody looking at a list of 200 messages, all with subjects like Simple Question or PostgreSQL Question, would decide to look at yours. I will do this in the future. drv_time = 478 / 45.0; The value of this is: 10.6222 Is there a way of converting this value to an interval. It seems that INTERVAL only works with a quoted literal value. You can do arithmetic on intervals: SELECT 478 / 45.0 * interval'1 hour'; I like your soultion better than mine. Thanks for the answer. For more information, see Date/Time Functions and Operators in the documentation. -- Michael Fuhr http://www.fuhr.org/~mfuhr/ ---(end of broadcast)--- TIP 8: explain analyze is your friend Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [SQL] Simple Question
Thanks for the reply. My answer was a little different than yours because I used 488 instead of 478. Well, that three ways so far ;o) On Tuesday 11 January 2005 05:06 pm, Guy Fraser saith: Convert to seconds first (3600 sec/hr) : select ( '3600'::int4 * '478'::int4 / '45.0'::float8 )::int4::reltime::interval ; interval -- 10:37:20 (1 row) I don't know if ::int4::reltime::interval is the best way to end up with an interval, but its the only way I could figure out how to do it off the top of my head. On Tue, 2005-11-01 at 16:42 -0500, Terry Lee Tucker wrote: Hello: I'm trying to figure out how to convert a floating point value into an interval of time. I'm calculating the time required to drive from point A to point B. For the sake of this question, we'll just say it is miles/speed. So: drv_time = 478 / 45.0; The value of this is: 10.6222 Is there a way of converting this value to an interval. It seems that INTERVAL only works with a quoted literal value. If I type: rnd=# select interval '10.8444 hours'; interval @ 10 hours 50 mins 40 secs (1 row) Anybody have an pointers? Thanks... Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster -- Guy Fraser Network Administrator The Internet Centre 1-888-450-6787 (780)450-6787 ---(end of broadcast)--- TIP 8: explain analyze is your friend Work: 1-336-372-6812 Cell: 1-336-363-4719 email: [EMAIL PROTECTED] ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
Re: [SQL] Simple Question
Terry Lee Tucker [EMAIL PROTECTED] writes: I'm trying to figure out how to convert a floating point value into an interval of time. Use something like regression=# select (478 / 45.0) * '1 hour'::interval; ?column? -- 10:37:20 (1 row) ... or whatever other scale factor you have in mind. regards, tom lane ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
Re: [SQL] simple question!
Esteban, is there a command intersect? I mean exist a union command, but I don't know if exist a intersect command. thanks Yes. There is also EXCEPT as well as INTERSECT and UNION. See the online docs, in SQL COMMANDS -- SELECT -Josh __AGLIO DATABASE SOLUTIONS___ Josh Berkus Complete information technology [EMAIL PROTECTED] and data management solutions (415) 565-7293 for law firms, small businessesfax 621-2533 and non-profit organizations. San Francisco ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
[SQL] Simple Question
Hello All, This may be the wrong mailing list for this question but I hope someone can answer it for me as it is holding up my development progress. I have now been able to compile the tutorial/complex.c functions and test them out with no problems. I made a copy of the Makefile, Makefile.global, and Makefile.port (Linux) from the tutorial directory and made a simple modification for the paths. Now the 'c" files compile up just fine. The problem is that this set up will not work if I make some C++ files. I think that there is something wrong in one of the above makefiles for the g++ compiler and the needed options, but do not know where to find it. I even made a copy of the "concat_text()" function from the manual and saved one copy as a "c" file. It compiled just fine. I then renamed that same file to "cc" for C++ and it compiled ok, but the psql command interperter gave me some error that it could not find the function even thout it worked the first time and I moade no other changes. I also need to link in some other libraries like "libfile.a" that I have for some of the functions that will be placed in my pgSQL interface but am not sure hoe to do this as well with the default Makefiles. Does someone have a simple Makefile that will allow me to compile up my C++ functions? Cheers, Lonnie __ Do You Yahoo!? Get email at your own domain with Yahoo! Mail. http://personal.mail.yahoo.com/ ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://www.postgresql.org/search.mpl
