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From: Georgios Petasis on 10 Jun 2010 05:17
στις 10/6/2010 04:33, O/H Kevin Kenny έγραψε:
> George Petasis wrote:
>> TDBC is cool :-)
>
> Good to hear.
>

I really liked the usage of tcl variables through the :varname syntax.
This was something that sqlite had, and I missed it in other databases,
i.e. postgres through pgintcl, which you had to do conversions from tcl
to postgres strings...

George
From: Donal K. Fellows on 10 Jun 2010 08:19
On 10 June, 10:17, Georgios Petasis <peta...(a)iit.demokritos.gr> wrote:
> I really liked the usage of tcl variables through the :varname syntax.
> This was something that sqlite had, and I missed it in other databases,
> i.e. postgres through pgintcl, which you had to do conversions from tcl
> to postgres strings...

This sort of best-practice is one of the reasons we did TDBC. (Or
rather, one reason why we encouraged Kevin to do TDBC. ;-))

Donal.
From: Georgios Petasis on 10 Jun 2010 12:34
στις 10/6/2010 04:33, O/H Kevin Kenny έγραψε:
> George Petasis wrote:
>> TDBC is cool :-)
>
> Good to hear.
>

Is there a array or a dict involved in foreach? Because the order rows
are examined seems different than in database:

http://www.ellogon.org/~petasis/tcl/Images/TDBC-foreach.png

My code is:
set list [list]
my foreach -as lists -- row \
{SELECT event_id, primary_event, title FROM events WHERE\
set_id = :default_set_id} {
lappend list $row
}
set events $list
(variable events is used as a list variable in a tablelist widget).

And method foreach, just calls tdbc::foreach:
method foreach {args} {
my variable db
my connect
catch { uplevel 1 [list $db foreach {*}$args] } result options
catch {my disconnect}
return -options $options $result
};# foreach

George
From: drscrypt on 10 Jun 2010 13:00
On 6/10/2010 12:34 PM, Georgios Petasis wrote:
> Is there a array or a dict involved in foreach? Because the order rows
> are examined seems different than in database:
>


I have not used TDBC but in general, a select from a database is not
guaranteed to return data in any particular order and may also differ in
subsequent runs. If you want a particular order, you can use an order
by clause.


DrS

From: tom.rmadilo on 10 Jun 2010 18:54
On Jun 10, 10:00 am, drscr...(a)gmail.com wrote:
> On 6/10/2010 12:34 PM, Georgios Petasis wrote:
>
> > Is there a array or a dict involved in foreach? Because the order rows
> > are examined seems different than in database:
>
> I have not used TDBC but in general, a select from a database is not
> guaranteed to return data in any particular order and may also differ in
> subsequent runs.  If you want a particular order, you can use an order
> by clause.

Absolutely essential that you use an order-by clause in every query.
For instance, postgreSQL is known to append updated rows to the bottom
of a table, so each update query changes the subsequent order of rows
returned without an order-by clause.
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