Hi, let me start with "No I have not executed the demo code";
but a couple of thinks that come to mind: 1) What version of FPC are you using (you only said you updated Lazarus); you refer to FPC 2.2.2, have you tried the fixes branch (2.2.3)? or trunc(2.3.1)? 2) You say you do not know the exact error: " because the popup box doesn't state it" => Try running the exe in the debugger, make sure you compile with debug symbols for gdb (-g, maybe also -gl). Or try to compile "not" as a windows app (switch off -WG) then you get a console window, and a lot of output. (Both options are in Project->compiler options->tab: linking) It could be in the RTL, in which case it would be helpful to rebuild this with debug support Good Luck waldo kitty wrote: > thanks for your response, reenen... it does tend to make sense on the one > hand > but on the other i "must" ask if you have looked at and/or run the demo code > i > pointed to? > > it does check if the connection is open ;) > > procedure TFormTryMySQL.ConnectButtonClick(Sender: TObject); > begin > // Check if we have an active connection. If so, let's close it. > if MySQLConnection1.Connected then begin > SQLTransaction1.Active := False; > MySQLConnection1.Close; > end; > blahfooblah...; > > when i place logging lines in the above, the last logging line that executes > is > the one right above "MySQLConnection1.Close;" which indicates the error in is > the "MySQLConnection1.Close;" library code... > > i can see where what you are saying may be possible but it doesn't make sense > because the next time the above is executed, it works "properly" (ie: there's > no > error).. > > what it almost sounds like is that in closing the connection object, > something > was not created during the open which somehow does get created during the > close... > > again, i dunno and that's why i'm here... one would think that demo code > should > work and work properly (ie: without error) out of the box... i won't point > back > to my comment about having problems with several other of the wiki demo apps > not > working for some reason or another :? > > > > Reenen Laurie wrote: > >> I am very uninformed when it comes to databases, but access violations >> happens when you do stuff to stuff that's not there. >> >> My guess is that for some reason your "close" code gets fired twice, and >> thus it's already closed by the time you get there the second time. >> >> So if there's a way to check if it's open, before you close it, I'd >> suggest try to close it inside an if open... >> >> Regards, >> -Reenen >> >> On Sun, Jan 18, 2009 at 9:39 PM, waldo kitty <[email protected] >> <mailto:[email protected]>> wrote: >> >> >> history: i'm a long time pascal coder... since TP3 first appeared on the >> market... then to TP5 and most of my time with TP6/BP6 and numerous >> commercial >> apps under my belt... i've dabbled with OOP stuffs, TP7/BP7 and even >> have a copy >> of delphi6-personal that i've not been able to wrap my head >> around... since my >> delphi was a downloaded copy from Inprise, it is also a bit harder >> to work with >> since i've no real documentation that i can lay in my lap to look >> over while >> working on code :? :( >> >> in any case, i've been fighting a battle with mysql50conn for a few >> weeks, >> now... i started with Lazaruz 0.9.26 and last night installed >> Lazarus 0.9.27 to >> see if the problem i'm facing may have been fixed in there but it >> has not and >> i'm not even certain if the problem is in the library code or >> possibly something >> on this old win98SE box :? >> >> ok, enough of the history and story telling... >> >> the details: with the tutorial DB code on the wiki (yeah, i was >> /finally/ able >> to get two or three of those working after some starts, stops and >> fits :P), >> there's several that check to see if the connection to the database >> is active >> and if it is, they attempt to close it... my problem is that the >> first attempt >> to close the connection _always_ throws an error... i don't know >> what specific >> error code because the popup box doesn't state it... the box only says >> >> Access violation. >> >> Press Ok to ignore and risk data corruption. >> Press Cancel to kill the program. >> >> [OK] [Cancel] >> >> i'm triggering my initial connection to the database via a button. i >> click the >> button, the connection takes place, data is retrieved, and the >> connection is >> attempted to close... that's when the error is thrown... however, if >> i hit the >> [OK] button to ignore the error then i can open and close the >> connection to the >> database with no problems... at least it appears that way because >> other routines >> gather other data from other tables and they all connect, gather, >> and disconnect >> without problems... all routines use the very same disconnect >> routine and this >> is what leads be to believe that there's something in the library >> code that's >> the problem... >> >> currently, all the code i'm using simply uses the close procedure of the >> connection object (ie: MySQL50Connection.Close)... i've only one >> graphical demo >> app that doesn't exhibit this problem but it is using mysql4 in the >> uses and a >> lot of manual code instead of the connector, transaction, and sqlquery >> objects... i also have the text modedemo app working and it doesn't >> have the >> problems either... now, i'm not sure, at all, if any of the (demo) >> apps i'm >> working with are using the libmysql.dll file that i placed in my >> windows/system(32?) directory or not... i believe that the textmode >> demo would >> not run without that dll but that was several weeks ago when i was >> playing with >> it and it was also in the plain FPC 2.2.2 installation i have/had on >> here before >> i figured out that Laz came with FPC in its tree... >> >> for those who want/need a link to example code that exhibits this >> problem, i'm >> using the downloaded code "TryMySQL5 Modified by Arwen" but i can't >> find the >> link in the wiki now :( in any case, this is the TryMySQL5 demo app >> with the >> fields for the server, username, and password rather than them being >> hardcoded... once you fill them in, then you click the [Connect] >> button to >> connect to the server and get a list of available databases... now >> you choose a >> database from the combo box and then click the [Select Database] >> button... it is >> at this point that the error is thrown when the connection is closed and >> reopened so the new database can be used... >> >> >> FWIW: >> here's the memo field "log" with the error point marked with '>>' >> and yes, i've >> slightly modified the "logging" to try to figure out where the error >> is taking >> place and every time the last line logged before the popup box >> appears is the >> one right above the mysql50connection.close line... >> >> 14:26:18: Opening a connection to server: ender >> 14:26:19: Connected to server: ender >> 14:26:19: Retreiving list of available databases. >> 14:26:19: Query ACTIVE and at the first record >> 14:26:19: List of databases received! >> >>14:26:26: Closing connection >> 14:26:33: Closing connection >> 14:26:33: Connection closed... >> 14:26:33: DatabaseComboBox.ItemIndex: 2 >> 14:26:33: DatabaseComboBox.Items[ItemIndex]: kims >> 14:26:33: setting SQL statement... >> 14:26:33: Retrieving list of tables >> 14:26:33: opening sql query... >> 14:26:34: List of tables received >> >> so, at 14:26:26, i clicked the [Select Database] button and then >> clicked the >> [OK] button in the error box and then i clicked on the [Select >> Database] button >> again (14:26:33)... >> >> so, there it is with all my wordiness and verbiage... oh, and the >> hidden subtle >> "am i linked?" test message ;) >> >> so, is it me or is it a bug in the library? if the library, which >> library? Laz >> stuff or FPC stuff? >> >> -- >> NOTE: NEW EMAIL ADDRESS!! >> >> _\/ >> (@@) Waldo Kitty, Waldo's Place USA >> __ooO_( )_Ooo_____________________ telnet://bbs.wpusa.dynip.com >> <http://bbs.wpusa.dynip.com> >> _|_____|_____|_____|_____|_____|_____ http://www.wpusa.dynip.com >> ____|_____|_____|_____|_____|_____|____ ftp://ftp.wpusa.dynip.com >> _|_Eat_SPAM_to_email_me!_YUM!__|_____ wkitty42 -at- windstream.net >> <http://windstream.net> >> >> >> --- >> avast! Antivirus: Outbound message clean. >> Virus Database (VPS): 090117-0, 01/17/2009 >> Tested on: 1/18/09 14:39:07 >> avast! - copyright (c) 1988-2009 ALWIL Software. >> http://www.avast.com >> >> >> >> _______________________________________________ >> Lazarus mailing list >> [email protected] <mailto:[email protected]> >> http://www.lazarus.freepascal.org/mailman/listinfo/lazarus >> >> >> >> >> -- >> o__ >> ,_.>/ _ >> (_)_\(_)_______ >> ...speed is good >> _______________ >> I believe five out of four people have a problem with fractions. >> > > > _______________________________________________ Lazarus mailing list [email protected] http://www.lazarus.freepascal.org/mailman/listinfo/lazarus
