Updated Table Returning Error When Query with ASP.NET Web API2 Service

0
votes

I'm working on a WindowsPhone 8.1 app, and I have a SQL database connected to a Web API server hosted on an Azure website. Recently, the database person updated the database, added a new table, and added sample data to the tables that didn't already have any. When managing the database through Azure, I can see that all the tables have data in them, but when I try to retrieve them with the /api/entityname url, it returns an error message.

A few things to note, the database the server connects to has changed since I originally published it. I tried to run the enable migrations and update database commands again, but I don't know how to select the new database it's now connected to. Do I need to republish the server? Run the migrations commands for the new database? I'm hesitant try things involving the database connection on my own since I don't know much about it and don't want to mess up any configurations. I have a .NET backend. Thanks in advance for the help.

Update:

I went into the Web.Config file of my Services project and changed catalog value in the connection string to the name of my new database. Now I get the following error when I try to get the games values using the /api/teams extention:

An error has occurred.The 'ObjectContent1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'.</ExceptionMessage><ExceptionType>System.InvalidOperationException</ExceptionType><StackTrace/><InnerException><Message>An error has occurred.</Message><ExceptionMessage>The 'GameTime' property on 'Game' could not be set to a 'System.TimeSpan' value. You must set this property to a non-null value of type 'System.Byte[]'. </ExceptionMessage><ExceptionType>System.InvalidOperationException</ExceptionType><StackTrace> at System.Data.Entity.Core.Common.Internal.Materialization.Shaper.ErrorHandlingValueReader1.GetValue(DbDataReader reader, Int32 ordinal) at System.Data.Entity.Core.Common.Internal.Materialization.Shaper.GetPropertyValueWithErrorHandling[TProperty](Int32 ordinal, String propertyName, String typeName) at lambda_method(Closure , Shaper ) at System.Data.Entity.Core.Common.Internal.Materialization.Shaper.HandleEntityAppendOnly[TEntity](Func2 constructEntityDelegate, EntityKey entityKey, EntitySet entitySet)
at lambda_method(Closure , Shaper ) at System.Data.Entity.Core.Common.Internal.Materialization.Coordinator1.ReadNextElement(Shaper shaper) at System.Data.Entity.Core.Common.Internal.Materialization.Shaper1.SimpleEnumerator.MoveNext() at System.Data.Entity.Internal.LazyEnumerator1.MoveNext() at WriteArrayOfGameToXml(XmlWriterDelegator , Object , XmlObjectSerializerWriteContext , CollectionDataContract ) at System.Runtime.Serialization.CollectionDataContract.WriteXmlValue(XmlWriterDelegator xmlWriter, Object obj, XmlObjectSerializerWriteContext context) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.WriteDataContractValue(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle) at System.Runtime.Serialization.XmlObjectSerializerWriteContext.SerializeWithoutXsiType(DataContract dataContract, XmlWriterDelegator xmlWriter, Object obj, RuntimeTypeHandle declaredTypeHandle) at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) at System.Runtime.Serialization.DataContractSerializer.WriteObject(XmlWriter writer, Object graph) at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content) at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext, CancellationToken cancellationToken) --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at System.Web.Http.WebHost.HttpControllerHandler.d__1b.MoveNext()

I think I'm making some progress, but I'm not very experienced with connecting apps to databases, so I'm hesitant to poke around. Thanks in advance for the help. I am using data-first migration (EF Designer from database). Also, the above error message is only displayed when I run the service locally via localhost. When I run it through it's hosted azurewebsites url, I get the following:

An error has occurred.

I assume this is due to my database updates not being published to the hosted site, correct? I'm using Firefox as my browser. If I use IE, I can't download or open the JSON file for the new entities.

1
azureasp.net-web-api2database-migration

1 Answers

1
votes

With the help of a friend, I managed to fix this problem. In case anyone comes across this post down the line, the problem was due to conflicting data types between the database and the server's data objects. A list of data type mappings between C# and SQL Server can be found at https://msdn.microsoft.com/en-us/library/cc716729%28v=vs.110%29.aspx. Match the data types according to the linked chart, and ensure that any other database constraints (ie: required, etc) are included in annotations. Also, make sure that you update any code in your server's context file to match the data type changes. For instance, I had the following code in my OnModelCreating method:

modelBuilder.Entity<Game>()
            .Property(e => e.GameTime)
            .IsFixedLength();

Once I changed GameTime to a DateTime property,.IsFixedLength(); no longer applied to it, so I had to comment it out. As you make these changes, you can test them out by debugging your server locally, but you'll have to publish it back to the url it's hosted on in order see the changes take place on your remote server. In my case, I had to republish my azurewebsites.net site. I hope this helps anyone down the line that has a similar issue.