Bob, I agree that in general, when dealing with a server, you are exactly right on what you should be doing. Since SQLite is a local file-store DB, it's a little different. it isn't designed for transaction loads, multi-users, etc. it doesn't even support all the datatypes - for instance, yes, you can define a boolean, but it isn't a boolean.
database servers require an entirely different class of developer, imho, otherwise all sorts of evil things will happen. On Fri, Apr 25, 2014 at 1:22 AM, Robert Sneidar <slylab...@me.com> wrote: > My experience with SQL is that there is a timeout if a connection has been > idle for a certain period of time. Perhaps this is not a problem with > sqLite, but as a matter of good development habits, get all the info you > need from the user BEFORE opening the connection, so that there is no > chance of having a user walk away from his desk while your app is wanting > something from him with an open connection. Once you open the connection, > do what you need to do, then close it. > > If you have anything like complex transactions where you may have to abort > all your inserts and updates mid stream, use transactions. This way you can > rollback midstream with no ill effects. If the connection goes stale, you > will find that the user will have to sit there for 30 seconds to a minute > or more waiting for the app to release so you can deal with the connection > timeout. Not pretty. > > I cannot tell you the hell and havoc I have had working with different > database applications where the developers figured, “What the hell, just > leave the connection open,” and then something happens network wise and the > application dumps to the desktop. That is crappy programming IMHO. > > Would you open an FTP session and just leave it open for convenience? How > about an HTTPS session? Think about how your bank works. If you are idle > for any length of time they kick you. If I am logged into a copier too long > for crying out loud That will kick me out! It’s my opinion at least that > every network or database connection should have some means of > disconnecting when idle. It’s just good practice. > > Bob S > > > On Apr 24, 2014, at 9:07 PM, Peter Haworth <p...@lcsql.com> wrote: > > > Hi James, > > I'd leave them open until you quit the app. You might also think about > > using the ATTACH command for the second and subsequent connections so > > they'll all be open on the same connection. This allows you to, for > > example, define JOINs across databases, although you'll need to change > the > > references to anything in the attached databases. > > > > Pretty sure you need to load extensions for each connection, so the > ATTACH > > approach will help there too. > > > > Pete > > lcSQL Software > > On Apr 24, 2014 7:49 PM, "James Hale" <ja...@thehales.id.au> wrote: > > > >> 1. Open and close database connections. When? > >> Obviously you need to open a connection to access a database, but when > do > >> you need to close it? > >> Does it close without you doing anything? > >> I have the need to connect to four db's while running my app. > >> Access to a couple of these is sporadic but constant across a user > session > >> with the app. > >> Can I just open a connection to them all on the app's launch and then > >> close the connection of quitting? Currently I reassert the connection on > >> most accesses. Is this a bad thing to do? > >> > >> 2. SQLite's new ability to load a runtime extension. What does it attach > >> to? > >> I have compiled a couple of extensions to SQLite for my app. I use them > in > >> two distinct db's that I connect to. Do I need to load the extension for > >> each db or only once. > >> In other words is it loaded for the engine itself or does the load only > >> apply to the specific database I am connecting to at the time? > >> > >> Thanks in advance > >> > >> James > >> _______________________________________________ > >> use-livecode mailing list > >> use-livecode@lists.runrev.com > >> Please visit this url to subscribe, unsubscribe and manage your > >> subscription preferences: > >> http://lists.runrev.com/mailman/listinfo/use-livecode > >> > > _______________________________________________ > > use-livecode mailing list > > use-livecode@lists.runrev.com > > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > > http://lists.runrev.com/mailman/listinfo/use-livecode > > > _______________________________________________ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your > subscription preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode > -- On the first day, God created the heavens and the Earth On the second day, God created the oceans. On the third day, God put the animals on hold for a few hours, and did a little diving. And God said, "This is good." _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
