Entity Framework 6 with Mysql and NullReferenceException

Wednesday, July 2, 2014

When I try to insert same data I am getting NullReferenceException exception.


I have read tons of posts in Stackoverflow, asp.net forums and mysql community forums. I could not found any true solution for this problem. There is a lots of answer about that. However anyone solved my problem (also another people's problems). I found some bug reports about problem like that. However every reports should solved in .Net Connector 6.8.3. I think I am missing very simple step in EF with Mysql but I could not found what is my mistakes...


Sample Code:



using (prodEntities myEntity = new prodEntities ())
{
userloginlog log = new userloginlog();
log.UserRef = pUserID;
log.Success = pSuccess;
log.IpNo = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();
log.BrowserInfo = browserInfo;
log.LoginTime = GeneralHelperC.getCompanyDateTime();
myEntity.userloginlog.Add(log);
myEntity.SaveChanges();
}


Table:



CREATE TABLE `userloginlog` (
`RID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`UserRef` bigint(20) unsigned NOT NULL,
`LoginTime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`IpNo` varchar(15) DEFAULT NULL,
`Success` tinyint(4) NOT NULL,
`BrowserInfo` varchar(1000) DEFAULT NULL,
PRIMARY KEY (`RID`),
KEY `userLoginLog_Staff_Key` (`UserRef`),
CONSTRAINT `UserLoginLog_User_Key` FOREIGN KEY (`UserRef`) REFERENCES `users` (`RID`)
) ENGINE=InnoDB AUTO_INCREMENT=16903 DEFAULT CHARSET=utf8;


Exception:



at MySql.Data.Entity.ListFragment.WriteSql(StringBuilder sql)
at MySql.Data.Entity.SelectStatement.WriteSql(StringBuilder sql)
at MySql.Data.Entity.InsertStatement.WriteSql(StringBuilder sql)
at MySql.Data.Entity.SqlFragment.ToString()
at MySql.Data.Entity.InsertGenerator.GenerateSQL(DbCommandTree tree)
at MySql.Data.MySqlClient.MySqlProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree)
at System.Data.Entity.Core.Common.DbProviderServices.CreateDbCommandDefinition(DbProviderManifest providerManifest, DbCommandTree commandTree, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.Common.DbProviderServices.CreateCommandDefinition(DbCommandTree commandTree, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.Common.DbProviderServices.CreateCommand(DbCommandTree commandTree, DbInterceptionContext interceptionContext)
at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree)
at System.Data.Entity.Core.Mapping.Update.Internal.DynamicUpdateCommand.CreateCommand(Dictionary`2 identifierValues)
at System.Data.Entity.Core.Mapping.Update.Internal.DynamicUpdateCommand.Execute(Dictionary`2 identifierValues, List`1 generatedValues)
at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.<Update>b__2(UpdateTranslator ut)
at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[T](T noChangesResult, Func`2 updateFunction)
at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update()
at System.Data.Entity.Core.Objects.ObjectContext.<SaveChangesToStore>b__d()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(SaveOptions options, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction)
at System.Data.Entity.Core.Objects.ObjectContext.<>c__DisplayClassb.<SaveChangesInternal>b__8()
at System.Data.Entity.Infrastructure.DefaultExecutionStrategy.Execute[TResult](Func`1 operation)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(SaveOptions options, Boolean executeInExistingTransaction)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(SaveOptions options)
at System.Data.Entity.Internal.InternalContext.SaveChanges()
at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
at System.Data.Entity.DbContext.SaveChanges()


Installed in my computer:



  • Mysql Server 5.6CE

  • MySQL Connector NET 6.8.3

  • Visual Studio 2013


Refenced DLL's in project (everyone installed with nuget):



  • MySql.Data.dll (6.8.3)

  • MySql.Data.Entity.dll (6.7.5)

  • MySql.Data.Entities.dll (6.8.3.0)

  • MySql.Web.dll (6.8.3)

  • EntityFramework.dll (6.1.1)


Project is Asp.Net Webform which running under .Net Framework 4.0


Thank you very much







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