BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Working with Query results          BorlandTalk.com Forum Index -> C++ Builder Databases (SQL Servers) View previous topic :: View next topic   Author Message Anthony Guest Posted: Tue Apr 11, 2006 1:03 am    Post subject: Working with Query results I have an Access Database with several tables configured and using TQuery components to select the records to work with. I have the queries working fine and obtain the records I need, but my issue comes when I try to work the data of an individual record. Not all of the records have all of the fields populated and this seems to be causing Builder some problems. I would like to do the following: Label1->Caption = TQuery1->FieldValues["Field1"]->AsString but if the result is empty it crashes. What I have had to do is check each item of each record before I use like this: if (TQuery->FieldValues["Field1"] != Variant.ChangeType(varNull)) { Label1->Caption = TQuery1->FieldValues["Field1"]->AsString } Is there an easier or another way of doing this? Anthony Back to top Pedro Fehlauer Guest Posted: Wed Jul 05, 2006 7:54 pm    Post subject: Re: Working with Query results That's strange, it doesn't happen to me. If a NULL field is assing to a string type, it should shield an empty string. Are you using ODBC? Maybe some setting in the datalink... Pedro <Anthony> escribió en el mensaje news:ptvl32td10qs6tbcu4l7p4gtrjekl9f1kd (AT) 4ax (DOT) com... Quote: I have an Access Database with several tables configured and using TQuery components to select the records to work with. I have the queries working fine and obtain the records I need, but my issue comes when I try to work the data of an individual record. Not all of the records have all of the fields populated and this seems to be causing Builder some problems. I would like to do the following: Label1->Caption = TQuery1->FieldValues["Field1"]->AsString but if the result is empty it crashes. What I have had to do is check each item of each record before I use like this: if (TQuery->FieldValues["Field1"] != Variant.ChangeType(varNull)) { Label1->Caption = TQuery1->FieldValues["Field1"]->AsString } Is there an easier or another way of doing this? Anthony Back to top Anthony Guest Posted: Thu Jul 06, 2006 6:03 am    Post subject: Re: Working with Query results I'm not sure on the ODBC. But I don't think so. I am using Borland 5 and MSAccess database through TQuery components. Are you using TQuery1->FieldValue["Field1"]->AsString or are you using TQuery1->FieldByName("Field1")->AsString? I have read many places that FieldValues is the preferred method, but also have found the overhead required as I described below. I have avoided much of the overhead by using FieldByName. Am I going in the right direction? I hope so since I have just started alpha testing on the application. Anthony On Wed, 5 Jul 2006 09:54:38 -0500, "Pedro Fehlauer" <info@sistemas-especificos.com> wrote: Quote: That's strange, it doesn't happen to me. If a NULL field is assing to a string type, it should shield an empty string. Are you using ODBC? Maybe some setting in the datalink... Pedro Anthony> escribió en el mensaje news:ptvl32td10qs6tbcu4l7p4gtrjekl9f1kd (AT) 4ax (DOT) com... I have an Access Database with several tables configured and using TQuery components to select the records to work with. I have the queries working fine and obtain the records I need, but my issue comes when I try to work the data of an individual record. Not all of the records have all of the fields populated and this seems to be causing Builder some problems. I would like to do the following: Label1->Caption = TQuery1->FieldValues["Field1"]->AsString but if the result is empty it crashes. What I have had to do is check each item of each record before I use like this: if (TQuery->FieldValues["Field1"] != Variant.ChangeType(varNull)) { Label1->Caption = TQuery1->FieldValues["Field1"]->AsString } Is there an easier or another way of doing this? Anthony Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> C++ Builder Databases (SQL Servers) 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.