BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  can't connect to interbase database before mainform creation          BorlandTalk.com Forum Index -> Delphi Databases (InterBase Express) View previous topic :: View next topic   Author Message HanslH Guest Posted: Mon Feb 12, 2007 3:22 pm    Post subject: can't connect to interbase database before mainform creation Lately i've taken effort to seperate all system initilialization from form initialization in my delphi turbo 2006 app. System init takes place in the intialization section of the app. I now find that init of my interbase (create component, set transaction, set password and connect) will not function here but the same routine doing this does function in the mainform.onshow event. The error I get otherwise reads: 7c918fea ntdll.dll RtlpWaitForCriticalSection 7c901046 ntdll.dll RtlEnterCriticalSection 0054b54a Pveterin.exe IBSQLMonitor MonitorHook 00542953 Pveterin.exe IBDatabase TIBDatabase.DoConnect 004cfbf1 Pveterin.exe DB TCustomConnection.SetConnected 006a8dab Pveterin.exe Uveterin 8988 TDataBaseholder.CreateIBDatabase 005d8d01 Pveterin.exe UVeterinExclusive 459 InitSys 0078729e Pveterin.exe UVeterinExclusive 527 initialization The routine: //======================================== procedure TDatabaseholder.CreateIBDatabase; var IB : TIBDatabase; i:integer; begin IBDatabase := TIBDatabase.create(self); IBTransaction := TIBTransaction.create(self); //members of tdatabaseholder class IB := IBDatabase; IB.connected := false; IB.defaultdatabase := IB; IB.defaulttransaction := IBTransaction; IB.databasename := 'C:\Veterin\Interbase\VETERIN.GDB'; IB.loginprompt := false; IB.Params.clear; IB.Params.Add( 'user_name=SYSDBA'); IB.Params.Add( 'password=masterkey'); IB.Params.Add('PAGE_SIZE 4096'); IB.connected := true; end; //======================================== How to solve? Back to top Bill Todd Guest Posted: Mon Feb 12, 2007 6:51 pm    Post subject: Re: can't connect to interbase database before mainform crea Where do you call the procedure? Are you saying that you call it from the initialization section of some unit? What is TDatabaseholder? -- Bill Todd (TeamB) Back to top HanslH Guest Posted: Mon Feb 12, 2007 7:02 pm    Post subject: Re: can't connect to interbase database before mainform crea On 12 Feb 2007 04:51:13 -0800, "Bill Todd" <no (AT) no (DOT) com> wrote: Quote: Where do you call the procedure? Are you saying that you call it from the initialization section of some unit? What is TDatabaseholder? TDatabaseholder is just a TComponent descendent I created to make all my database activity more surveyable and to give all databasecomponents a parent because I specifically not want to be some form to be the parent. I have a special system initialization unit in which initialization and finilazation sections take care of the start and end of my program. If I call the procedure somewhere there the error is present, if I put it in the mainform.onshow event or at some menupress event all goes well. Initialization is divided in processes that don't need the database yet and processes that do, so if I should be forced to iniitialize my ibdatabase on a form I might as well drop the whole idea of initialization and form separation. Back to top Bill Todd Guest Posted: Mon Feb 12, 2007 7:17 pm    Post subject: Re: can't connect to interbase database before mainform crea HanslH wrote: Quote: I have a special system initialization unit in which initialization and finilazation sections take care of the start and end of my program. That will not work. You need to wait until the VCL has been initialized before you create database components and connect. Use the OnCreate event handler of the main form or data module. -- Bill Todd (TeamB) Back to top HanslH Guest Posted: Mon Feb 12, 2007 7:56 pm    Post subject: Re: can't connect to interbase database before mainform crea On 12 Feb 2007 05:17:56 -0800, "Bill Todd" <no (AT) no (DOT) com> wrote: Quote: HanslH wrote: I have a special system initialization unit in which initialization and finilazation sections take care of the start and end of my program. That will not work. You need to wait until the VCL has been initialized before you create database components and connect. Use the OnCreate event handler of the main form or data module. No, that won't do. Not even if it's the last thing in oncreate I do, it has to be onshow. And it does work for other database components like tadstable. Also I got positive feedback from a professional programmer that it is good programming practice to seperate the visual and non visual parts of a program. Back to top Wayne Niddery [TeamB] Guest Posted: Mon Feb 12, 2007 9:33 pm    Post subject: Re: can't connect to interbase database before mainform crea HanslH wrote: Quote: No, that won't do. Not even if it's the last thing in oncreate I do, it has to be onshow. And it does work for other database components like tadstable. Also I got positive feedback from a professional programmer that it is good programming practice to seperate the visual and non visual parts of a program. Yes it is good to separate these things. However, it appears you have not actually separated and removed the *dependencies*. The same code you show indicates you have global variables somewhere - IBDatabase and IBTransaction - are they part of DatabaseHolder or are they declared elsewhere? Where is the Databaseholder class created (is it created)? You assign this as the owner of the database components, in fact you do not need to assign *anything* as the owner in this case. The problem here is by assigning the owner, the VCL starts sending component messages around before the VCL is ready. Descend your DatabaseHolder class from TObject not TComponent - there's no need for it it be a component. -- Wayne Niddery - Winwright, Inc (www.winwright.ca) "At the apex of every great tragedy of mankind there stands the figure of an incorruptible altruist." - Ayn Rand Back to top HanslH Guest Posted: Tue Feb 13, 2007 12:26 am    Post subject: Re: can't connect to interbase database before mainform crea On Mon, 12 Feb 2007 10:33:41 -0500, "Wayne Niddery [TeamB]" <wniddery (AT) chaffaci (DOT) on.ca> wrote: Quote: HanslH wrote: No, that won't do. Not even if it's the last thing in oncreate I do, it has to be onshow. And it does work for other database components like tadstable. Also I got positive feedback from a professional programmer that it is good programming practice to seperate the visual and non visual parts of a program. Yes it is good to separate these things. However, it appears you have not actually separated and removed the *dependencies*. The same code you show indicates you have global variables somewhere - IBDatabase and IBTransaction - are they part of DatabaseHolder or are they declared elsewhere? In the code is a comment indicating they are members of TDatabaseholder. Quote: Where is the Databaseholder class created (is it created)? You assign this as the owner of the database components, in fact you do not need to assign *anything* as the owner in this case. The problem here is by assigning the owner, the VCL starts sending component messages around before the VCL is ready. The databaseholder is being created ever since I created my program 3 years ago as a 'holder' of all my tables. Also if I didn't create it, I would see access violations all over the place :-) Quote: Descend your DatabaseHolder class from TObject not TComponent - there's no need for it it be a component. I do because the tables i create want either nil or a component as owner. I'm not a OOP crack but it doesn't feel right to typecast like this mytable := tmyadstable.create(tcomponent(self)); BUT I solved it! By just changing the name of IBDatabase. It seems I was creating confusion between IBDatabase as my database and IBDatabase the unit. Back to top Bill Todd Guest Posted: Tue Feb 13, 2007 3:23 am    Post subject: Re: can't connect to interbase database before mainform crea HanslH wrote: Quote: No, that won't do. Not even if it's the last thing in oncreate I do, it has to be onshow. Then something is wrong. I do all of my data access connection setup in the OnCreate event handler and it has never failed. -- Bill Todd (TeamB) Back to top Wayne Niddery [TeamB] Guest Posted: Tue Feb 13, 2007 4:03 am    Post subject: Re: can't connect to interbase database before mainform crea HanslH wrote: Quote: Descend your DatabaseHolder class from TObject not TComponent - there's no need for it it be a component. I do because the tables i create want either nil or a component as owner. I'm not a OOP crack but it doesn't feel right to typecast like this mytable := tmyadstable.create(tcomponent(self)); No need, non-visual components like TAdsTable do not need owners, the only reason for providing an owner is that it allows the assigned owner to take responsibility for destroying the owned components, so when your DatabaseHolder instance is freed, it will take down the database components for you. However it is trvial to free these components yourself in an overridden destructor for your DatabaseHolder class. Then you only need: mytable := tmyadstable.create(nil); Quote: BUT I solved it! By just changing the name of IBDatabase. It seems I was creating confusion between IBDatabase as my database and IBDatabase the unit. Ah! Good stuff! <g> -- Wayne Niddery - Winwright, Inc (www.winwright.ca) SpaceShipOne; GovernmentZero Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> Delphi Databases (InterBase Express) All times are GMT Page 1 of 1   Jump to: Select a forum C++ Builder Newsgroups----------------C++ BuilderC++ Builder (ActiveX)C++ Builder (Announcements)C++ Builder (Command Line Tools)C++ Builder DatabasesC++ Builder Databases (ADO)C++ Builder Databases (Desktop)C++ Builder Databases (InterBase Express)C++ Builder Databases (Multi-Tier)C++ Builder Databases (SQL Servers)C++ Builder (Graphics)C++ Builder (IDE)C++ Builder (Internet)C++ Builder (Internet Socket)C++ Builder (Internet Web)C++ Builder (Jobs)C++ Builder (Language)C++ Builder (Language C++)C++ Builder (Compatibility with MFC)C++ Builder (Native API)C++ Builder (Non-Technical)C++ Builder (Students)C++ Builder (Third Party Tools)C++ Builder (Upgrade)C++ Builder (VCL)C++ Builder (VCL Components Usage)C++ Builder (VCL Components Development)C++ Builder (VCL Usage)C++ Builder (WinAPI)C++ Builder Installation Delphi Newsgroups----------------Delphi (General)Delphi ActiveX Controls UsageDelphi ActiveX Controls DevelopmentDelphi As400Delphi DatabasesDelphi Databases (ADO)Delphi Databases (dbExpress)Delphi Databases (Desktop)Delphi Databases (InterBase Express)Delphi Databases (Multi-Tier)Delphi Databases (SQL Servers)Delphi DeploymentDelphi GraphicsDelphi IDEDelphi InternationalizationDelphi InternetDelphi Internet Isapi-WebBrokerDelphi Internet WebSnapDelphi Internet WinsockDelphi JobsDelphi Language BASMDelphi Language ObjectPascalDelphi Model Driven Architecture (General)Delphi Model Driven Architecture (Third Party)Delphi MultimediaDelphi Native APIDelphi Non-TechnicalDelphi ObjectPascalDelphi OLE AutomationDelphi OO designDelphi OpenToolsAPIDelphi Reporting-ChartingDelphi RTLDelphi StudentsDelphi TeamSourceDelphi Thirdparty ToolsDelphi Thirdparty Tools (General)Delphi Thirdparty Tools (IntraWeb)Delphi Thirdparty Tools (RaveReports)Delphi UpgradeDelphi VCLDelphi VCL ComponentsDelphi VCL Components UsingDelphi VCL Components WritingDelphi WebServices SOAPDelphi WinAPIDelphi XMLDelphi Installationcomp.lang.pascal.delphi.components.misccomp.lang.pascal.delphi.components.usagecomp.lang.pascal.delphi.components.writingcomp.lang.pascal.delphi.databasescomp.lang.pascal.delphi.misccomp.sources.delphi JBuilder Newsgroups----------------JBuilderJBuilder AnnouncementsJBuilder Applet IssuesJBuilder As400JBuilder CompilerJBuilder CORBA/RMIJBuilder DatabasesJBuilder DB SwingJBuilder DebuggerJBuilder DeploymentJBuilder DocumentationJBuilder EnterpriseJBuilder HandheldJBuilder IDEJBuilder JavaJBuilder JavaAPIJBuilder Java LanguageJBuilder Java SwingJBuilder Java BeansJBuilder Java Beans UsageJBuilder Java Beans DevelopmentJBuilder JBCLJBuilder JDataStoreJBuilder JobsJBuilder LinuxJBuilder MacintoshJBuilder & MobileSetJBuilder MultiLingual AppsJBuilder Non-TechnicalJBuilder OpenToolsJBuilder Servlets (JSP)JBuilder StudentsJBuilder Team DevelopmentJBuilder Thirdparty ToolsJBuilder UpgradeJBuilder Installation InterBase Newsgroups----------------InterBaseInterBase Bug DiscussionInterBase GeneralInterBase IBConsoleInterBase OpenSourceInterBase ReplicationInterBase SQLInterBase ThirdpartyInterBase Installation Miscellaneous Borland Newsgroups----------------AppCenterAppServerEnteraVisiBroker  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.