BorlandTalk.com Borland discussion newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Null values          BorlandTalk.com Forum Index -> comp.lang.pascal.delphi.databases View previous topic :: View next topic   Author Message Rashid Guest Posted: Fri Jan 02, 2004 11:18 am    Post subject: Null values hi all, i am trying to check for null values in date columns but without any luck. Fields[0].AsDateTime <> 0 then ......... If Fields[0] contains a date everything is ok. But if it contains null, then i get an error. how do i return a false value if fields[0] is a null value. thanks in advance rashid Back to top Mike Shkolnik Guest Posted: Fri Jan 02, 2004 11:35 am    Post subject: Re: Null values Check the IsNull property for TField: if Fields[0].IsNull then <...> -- With best regards, Mike Shkolnik E-mail: [email]mshkolnik (AT) scalabium (DOT) com[/email] WEB: http://www.scalabium.com "Rashid" <mra (AT) pacific (DOT) net.sg> wrote Quote: hi all, i am trying to check for null values in date columns but without any luck. Fields[0].AsDateTime <> 0 then ......... If Fields[0] contains a date everything is ok. But if it contains null, then i get an error. how do i return a false value if fields[0] is a null value. thanks in advance rashid Back to top Rashid Guest Posted: Fri Jan 02, 2004 12:02 pm    Post subject: Re: Null values thanks mike but i still getting error after using your advice: Project GATSSql.exe raised exception class EVariantInValudArgError with message 'Invalid argument'. I checked my data, only the records with the null values are giving this problems. any ideas? rashid "Mike Shkolnik" <mshkolnik2002 (AT) ukr (DOT) net> wrote Quote: Check the IsNull property for TField: if Fields[0].IsNull then ... -- With best regards, Mike Shkolnik E-mail: [email]mshkolnik (AT) scalabium (DOT) com[/email] WEB: http://www.scalabium.com "Rashid" <mra (AT) pacific (DOT) net.sg> wrote in message news:bt3j12$k4o$1 (AT) mawar (DOT) singnet.com.sg... hi all, i am trying to check for null values in date columns but without any luck. Fields[0].AsDateTime <> 0 then ......... If Fields[0] contains a date everything is ok. But if it contains null, then i get an error. how do i return a false value if fields[0] is a null value. thanks in advance rashid Back to top Dan Guest Posted: Fri Jan 02, 2004 7:53 pm    Post subject: Re: Null values Have you stepped through this part of your program with the debugger? Mike is right in using the IsNull test. Do you get the error when this test is executed, or is it happening somewhere else? Dan On Fri, 2 Jan 2004 20:02:02 +0800, "Rashid" <mra (AT) pacific (DOT) net.sg> wrote: Quote: thanks mike but i still getting error after using your advice: Project GATSSql.exe raised exception class EVariantInValudArgError with message 'Invalid argument'. I checked my data, only the records with the null values are giving this problems. any ideas? rashid Back to top pr Guest Posted: Sat Jan 03, 2004 4:49 am    Post subject: Re: Null values "Rashid" <mra (AT) pacific (DOT) net.sg> wrote Quote: thanks mike but i still getting error after using your advice: Project GATSSql.exe raised exception class EVariantInValudArgError with message 'Invalid argument'. I checked my data, only the records with the null values are giving this problems. any ideas? rashid You obviously do something with the date after you test for null. Now, NULL is not a value but a *state* indicating *no value* which, depending on the database engine you use, cannot be processed like real field values. Some dbEngines may return 0 or '' for a null field thus masking this. PR Quote: "Mike Shkolnik" <mshkolnik2002 (AT) ukr (DOT) net> wrote in message news:bt3l7j$2m2e$1 (AT) news (DOT) dg.net.ua... Check the IsNull property for TField: if Fields[0].IsNull then ... -- With best regards, Mike Shkolnik E-mail: [email]mshkolnik (AT) scalabium (DOT) com[/email] WEB: http://www.scalabium.com "Rashid" <mra (AT) pacific (DOT) net.sg> wrote in message news:bt3j12$k4o$1 (AT) mawar (DOT) singnet.com.sg... hi all, i am trying to check for null values in date columns but without any luck. Fields[0].AsDateTime <> 0 then ......... If Fields[0] contains a date everything is ok. But if it contains null, then i get an error. how do i return a false value if fields[0] is a null value. thanks in advance rashid Back to top Jamie Guest Posted: Sun Jan 04, 2004 7:37 am    Post subject: Re: Null values you may want to try this first. If assigned(Fields) Then If Fields[0].ASDateTime <> 0 then... some of that way. Rashid wrote: Quote: hi all, i am trying to check for null values in date columns but without any luck. Fields[0].AsDateTime <> 0 then ......... If Fields[0] contains a date everything is ok. But if it contains null, then i get an error. how do i return a false value if fields[0] is a null value. thanks in advance rashid Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         BorlandTalk.com Forum Index -> comp.lang.pascal.delphi.databases 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.