On 1/10/08, Eric Butera <eric.butera@xxxxxxxxx> wrote:
>
> On Jan 10, 2008 2:02 PM, Philip Thompson <philthathril@xxxxxxxxx> wrote:
> > On Jan 10, 2008, at 12:48 PM, Eric Butera wrote:
> >
> > > On Jan 10, 2008 1:33 PM, <reese@xxxxxxxxxxxxxxxx> wrote:
> > >> I have been using define to create a constant for the link resource
> > >> returned by mysql
> > >> pconnect like so:
> > >>
> > >> $PL = @mysql_pconnect("localhost", $DBUser, $DBPass);
> > >> define("SITE_DB",$PL);
> > >>
> > >>
> > >> Later I use the constant to select my databases.
> > >>
> > >> mysql_select_db($SrcdbID ,SITE_DB);
> > >>
> > >> This code seems to be working as I expected and I have many
> > >> thousands of llines of code
> > >> done over several years using this construct.
> > >>
> > >> But, I happened to be reading the php doco today and noticed that
> > >> you are not supposed to
> > >> use define for resources, so question is, is what I am doing safe
> > >> or am I going to run into
> > >> problems and if so what is the best way to globally pass resources
> > >> to multiple classes and
> > >> functions, command line scripts etc?
> > >>
> > >>
> > >> Cheers
> > >> Charlie Reese
> > >>
> > >>
> > > Hi Charlie!
> > >
> > > Well a CONSTANT is a value that doesn't change. I don't think that
> > > makes sense for a DB connection. The connection command returns a
> > > resource that could be different on each request depending on if
> > > you've worked on different resources.
> > >
> > > You could just do this:
> > > $GLOBALS['SITE_DB'] = @mysql_pconnect("localhost", $DBUser, $DBPass);
> > >
> > > Then inside your function reference it like this:
> > > mysql_query($sql, $GLOBALS['SITE_DB']);
> > >
> > > This would be an easy mass find/replace that you could do. Global
> > > variables are evil though.
> > >
> > > I personally use the registry pattern to hold an instance of the
> > > database connection that can be lazy loaded whenever I need it. Then
> > > inside of my gateway objects I pass that instance in the constructor
> > > so they only have to know how to work with its interface. If you're
> > > okay with using object that might be a nice road to travel. You could
> > > also use the singleton pattern but I would advise against that because
> > > what if you wanted 2 instances for different databases? I've never
> > > ran across this myself but you never know. Plus it makes unit testing
> > > a little tricky since you can't mock it as easily.
> > >
> > > Hopefully something in all this will help you to an answer.
> >
> >
> > I don't agree that "Global variables are evil." If you have a valid
> > purpose for defining a global variable, then go with it. The usual
> > argument is that it could accidentally be changed elsewhere (and there
> > are several more). However, defining a variable that you KNOW you're
> > going to use only for a database connection, IMO, is perfectly fine.
> >
> > $GLOBALS['SITE_DB'] = @mysql_pconnect("localhost", $DBUser, $DBPass);
> >
> > If you accidently change $GLOBALS['SITE_DB'] elsewhere, then I think
> > you have some bigger issues at hand. =P HTH.
> >
> > ~Philip
> >
> > "Personally, most of my web applications do not have to factor 13.7
> > billion years of space drift in to the calculations, so PHP's rand
> > function has been great for me..." ~S. Johnson
> >
> > --
> >
> > PHP General Mailing List (http://www.php.net/)
> > To unsubscribe, visit: http://www.php.net/unsub.php
> >
> >
>
> Depending on what project I'm working on sometimes I use specific
> globals on our older procedural code because:
>
> 1) It is our code
> 2) It does not use outside code
> 3) I'm the only developer working on it
> 4) It is very simplistic
>
> By specific globals I mean that I have a "namespaced" entry such as
> $GLOBALS['ericonly']['db'] and put things inside of ericonly. I
> basically only use this for database connections and a few other very
> specific things.
>
> Aside from that I'm not going to argue the merits of globals. Someone
> else can do that as I've made up my mind and so have you. :)
>
> But just to prove that I'm right
> http://www.google.com/search?hl=en&q=global+variables+are+evil&btnG=Search
> :D
Well...
Personalized Results *1* - *10* of about *121,000* for
*global<http://www.google.com/url?sa=X&oi=dict&ei=InGGR9TUIYO6gATv4ZHKBg&sig2=rv83RnqqLJDobfnA3d78Lg&q=http://www.answers.com/global%26r%3D67&usg=AFQjCNF3eQaMYwTOPeOFmY3o3_vKZoxD3g>
variables<http://www.google.com/url?sa=X&oi=dict&ei=InGGR9TUIYO6gATv4ZHKBg&sig2=PtlnDj6B_ES74-UoJFdoYg&q=http://www.answers.com/variables%26r%3D67&usg=AFQjCNHUllfcxecDiCBZ124r8p5KyQoZlQ>are
evil<http://www.google.com/url?sa=X&oi=dict&ei=InGGR9TUIYO6gATv4ZHKBg&sig2=QHGtFJrSLNf_0ARuYMWpHA&q=http://www.answers.com/evil%26r%3D67&usg=AFQjCNF5_Fag6ntgqNkFzuWVU9bEyb717Q>
*. (*0.10* seconds)
Personalized Results *1* - *10* of about *4,330,000* for
*global<http://www.google.com/url?sa=X&oi=dict&ei=83CGR832BpbAggSao-G9Bg&sig2=b4uu-ZcrCZM0QWEXalxTNA&q=http://www.answers.com/global%26r%3D67&usg=AFQjCNH3VaZGgornyBLBavFsd_hljiBXsA>
variables<http://www.google.com/url?sa=X&oi=dict&ei=83CGR832BpbAggSao-G9Bg&sig2=kto8MuCLr5saX5VPjN8ThQ&q=http://www.answers.com/variables%26r%3D67&usg=AFQjCNF1uZkzAKhsWmdBCI0IzFzgLSEAhA>are
good<http://www.google.com/url?sa=X&oi=dict&ei=83CGR832BpbAggSao-G9Bg&sig2=ntLt-I0PIDJMXBMCk4OXCg&q=http://www.answers.com/good%26r%3D67&usg=AFQjCNHkthOJTyoPGlW9T2kzBpRwIqBc_A>
*. (*0.25* seconds)
Sorry, I couldn't resist. ;-)
David
