Re: date ranges in where

[Miguel Miranda <miguel.mirandag@xxxxxxxxx>]

Well, i tried all your sugestions, and i found some funny issues, i use the query to count exactly in a day by day basis, and running the query with 

WHERE lastlogin >= '2009-05-01' AND lastlogin < '2009-05-03'

OR 

WHERE lastlogin >= 'X' AND lastlogin <= 'Y' + '1 day'::interval


it includes the 0 hours of day 3:

05-02-2009 12:00:00 AM 

The exact result are from running:

....between '2009-05-01 00:00'::timestamp
        and '2009-05-02 23:59:59'::timestamp

but i select the ranges from a web form using a textbox, and right now i dont have a java calendar at hand, i tried this with good result:

WHERE lastlogin::date BETWEEN  '2009-05-01' AND '2009-05-02'

But now the query uses seq scan and not the index in lastlogin column.

Is there another way?

On Wed, May 6, 2009 at 3:17 PM, Erik Jones <ejones@xxxxxxxxxxxxxx> wrote:

On May 6, 2009, at 2:12 PM, Miguel Miranda wrote:

Hi, what is the recommended way to select a range of dates?

Lets say a have a table with a lastlogin (timestamp) column and i want toknow what users logged in for last time between 2009-05-01 and 2009-05-02?

I know that a simple

where lastlogin between '2009-05-01' and '2009-05-02' doesnt work beacuse it doesnt include who logged in 2009-05-02 15:30:00, etc...

WHERE lastlogin >= '2009-05-01' AND lastlogin < '2009-05-03'

or, if the values have are some unknown X and Y dates then you can do this:

WHERE lastlogin >= 'X' AND lastlogin <= 'Y' + '1 day'::interval

Erik Jones, Database Administrator
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