"Jordan Hayes" <[EMAIL PROTECTED]> wrote:
> I just downloaded Tcl bindings for 3.3.13 and am having trouble with
> some code that I wrote last year. Here's my code:
>
> load tclsqlite3.dll Sqlite3
> sqlite3 db foo.sqb
>
> set q1 "SELECT DATETIME('now','localtime','start of day') today"
> db eval $q1 x {
> set today $x(today)
> puts "today = $today"
> }
>
> set dq "SELECT DATETIME('$today','localtime','start of day','-1 days')
> t1,"
> append dq " DATETIME('$today','localtime','start of day','+1 days') t3"
> db eval $dq x {
> set yesterday [lindex $x(t1) 0]
> set tomorrow [lindex $x(t3) 0]
> puts "yesterday=$yesterday tomorrow=$tomorrow"
> }
>
> Running this script, I get this:
>
> today = 2007-03-20 00:00:00
> yesterday=2007-03-18 tomorrow=2007-03-20
>
> Seems to be off somehow....
You appear to be apply the 'localtime' correction twice: once when
you initially compute "today" and then again before you apply
the "-1 day" and "+1 day" operators.
A date in SQLite is not an object that keeps a separate hidden
"actual date" behind the scenes. A date is just a string. When
you apply 'localtime' it does not set some display flag - it
actually changes the string. So you can apply 'localtime' multiple
times and it will keep shifting the date. For example, consider
this SQL:
SELECT 111, datetime('now');
SELECT 222, datetime('now','localtime');
SELECT 333, datetime('now','localtime','localtime');
SELECT 444, datetime('now','localtime','localtime','localtime');
The output is:
111|2007-03-21 01:44:03
222|2007-03-20 21:44:03
333|2007-03-20 17:44:03
444|2007-03-20 13:44:03
With that in mind, go back and remove the extra 'localtime'
modifier and I think your code will work.
--
D. Richard Hipp <[EMAIL PROTECTED]>
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