When using the same MVC 3 & C# code along with copies of the same MySql 5.5 database on 2 different MySql installations. One works perfectly while the other one fails with an "Object must implement IConvertible" error. When I run the query against my local PC's MySql installation the query always works perfectly, but when I try querying from local PC's Visual Studio 2010 to a copy of the same database at my Internet Service Provider's MySql installation then I receive an error "Object must implement IConvertible". The only thing I change in the code is the ConnectionString's Server Name in the web.config, otherwise the code & database are exactly the same. NOTE: All other queries to the ISP's MySql installation work perfectly only this one particular query doesn't work.
After trying to troubleshoot this for several days I'm convinced that the error message "Object must implement IConvertible" has nothing to do with what is actually happening and I'm also under the impression that the MySql configuration at my ISP may somehow be causing this issue for the following reasons:
If this were truly an "Object must implement IConvertible" issue within the code then the issue would persist in the code and happen no matter which DB installation I hit.
I've completely dropped & recreated the DB at the ISP from my local PC's working copy however still receive the same exactly error.
MOST INTERESTINGLY is that the query has 3 nested IEnumerable lists that are all setup in the same way as IEnumerables and if I comment out any 1 of these nested lists in the query then the query runs successfully against the ISP's DB. It doesn’t matter which nested list gets commented out, only that there are 2 or less nested lists and then the query to the DB at ISP works. This is what leads me to the conclusion that MySql’s configuration at the ISP may be limiting my queries in some way, as I do not have this problem when querying my local PC's MySql installation. The error message really doesn’t appear to apply to what is actually happening. Again, all the other queries to the ISP's MySql installation work perfectly, however none of them contain more than 2 nested IEnumerable lists where this particular query contains 3?
Query Error "Object must implement IConvertible"
Server Error in '/' Application.
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Object must implement IConvertible.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidCastException: Object must implement IConvertible.
Source Error:
Line 392:
Line 393:
Line 394: var query =
Line 395: (from p in db.products
Line 396: where p.ClientId == clientId
Source File: C:\Users\JR\Documents\Visual Studio 2010\Projects\Subversion\ReservarMVC\ReservarMVC\Models\ProductRepository.cs Line: 394
Stack Trace:
[InvalidCastException: Object must implement IConvertible.]
System.Convert.ChangeType(Object value, Type conversionType, IFormatProvider provider) +9528453
MySql.Data.Entity.EFMySqlDataReader.ChangeType(Object sourceValue, Type targetType) +566
MySql.Data.Entity.EFMySqlDataReader.GetValue(Int32 ordinal) +231
System.Data.Common.Internal.Materialization.ErrorHandlingValueReader`1.GetValue(DbDataReader reader, Int32 ordinal) +215
System.Data.Common.Internal.Materialization.Shaper.GetColumnValueWithErrorHandling(Int32 ordinal) +46
lambda_method(Closure , Shaper ) +180
System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper) +170
System.Data.Common.Internal.Materialization.RowNestedResultEnumerator.MoveNext() +235
System.Data.Common.Internal.Materialization.ObjectQueryNestedEnumerator.TryReadToNextElement() +49
System.Data.Common.Internal.Materialization.ObjectQueryNestedEnumerator.ReadElement() +29
System.Data.Common.Internal.Materialization.ObjectQueryNestedEnumerator.MoveNext() +68
System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +327
System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
ReservarMVC.Models.ProductRepository.GetProductList(Nullable`1 dateStart, Nullable`1 dateEnd, Nullable`1 personQuantityId, Nullable`1 roomQuantityId) in C:\Users\JR\Documents \Visual Studio 2010\Projects\Subversion\ReservarMVC\ReservarMVC\Models\ProductRepository.cs:394
ReservarMVC.Models.ProductRepository.GetProductListSearch(Nullable`1 dateStart, Nullable`1 dateEnd, Nullable`1 personQuantityId, Nullable`1 roomQuantityId) in C:\Users\JR\Documents\Visual Studio 2010\Projects\Subversion\ReservarMVC\ReservarMVC\Models\ProductRepository.cs:605
ReservarMVC.Controllers.PortalController.MyExcurcion(ProductListSearchVM viewModel) in C:\Users\JR\Documents\Visual Studio 2010\Projects\Subversion\ReservarMVC\ReservarMVC\Controllers\PortalController.cs:63
lambda_method(Closure , ControllerBase , Object[] ) +162
System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +17
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +208
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +55
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +263
System.Web.Mvc.<>c__DisplayClass17.<InvokeActionMethodWithFilters>b__14() +19
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +191
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +343
System.Web.Mvc.Controller.ExecuteCore() +116
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +97
System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10
System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +37
System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +21
System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +12
System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +50
System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +7
System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8967601
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184
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Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.261
LINQ-to-Entities Query:
public IEnumerable<ProductListVM> GetProductList(DateTime? dateStart, DateTime? dateEnd, int? personQuantityId, int? roomQuantityId)
{
var query =
(from p in db.products
where p.ClientId == clientId
where p.ProductTypeId == 5
where personQuantityId <= p.Capacity
where roomQuantityId <= p.Quantity
select new ProductListVM
{
ProductId = p.ProductId,
ClientId = p.ClientId,
Name = p.Name_en,
Title = p.Title_en,
Description = p.Description_en,
Quantity = p.Quantity,
Capacity = p.Capacity,
newbookings = from b in db.bookings
where b.ProductId == p.ProductId
from res in db.reservations
where b.ReseravationId == res.ReservationId
where b.BookingDateTime >= dateStart && b.BookingDateTime <= dateEnd && res.ReservationStateId != 3
select new BookingVM
{
ProductId = b.ProductId,
BookingId = b.BookingId,
ClientId = b.ClientId,
ReservationId = b.ReseravationId,
BookingDateTime = b.BookingDateTime
},
newratecategories = from prc in db.productratecategories
where prc.ProductId == p.ProductId
from rc in db.ratecategories
where prc.RateCategoryId == rc.RateCategoryId
where (dateStart >= rc.DateStart && dateEnd <= rc.DateEnd) || (dateStart >= rc.DateStart || dateEnd <= rc.DateEnd)
select new MegaRateCategoryVM
{
RateCategoryId = rc.RateCategoryId,
DateStart = rc.DateStart,
DateEnd = rc.DateEnd
},
newproductimages = (from pi in db.productimages
where pi.ProductId == p.ProductId
from ig in db.imagegalleries
where pi.ImageGalleryId == ig.ImageGalleryId
select new MegaProductImageVM
{
ig_Description = ig.ig_Description,
ImageGalleryId = pi.ImageGalleryId
}).OrderByDescending(i => i.ImageGalleryId)
}).ToList();
return query;
}
Product List ViewModel:
namespace Project.ViewModels
{
[Serializable]
public class ProductListVM : BaseViewModel
{
public int ProductId { get; set; }
public int? ClientId { get; set; }
public int? ProductTypeId { get; set; }
public int? ProductStateId { get; set; }
public String Name { get; set; }
public String Title { get; set; }
public String Description { get; set; }
public int? Quantity { get; set; }
public int? Capacity { get; set; }
//PRODUCTIMAGE table fields
public IEnumerable<MegaProductImageVM> newproductimages { get; set; }
//RATECATEGORY table fields
public IEnumerable<MegaRateCategoryVM> newratecategories { get; set; }
//BOOKING table fields
public IEnumerable<BookingVM> newbookings { get; set; }
}
}
What could be causing this behavior? Could this be caused by a query threshold setting or network setting on the MySql 5.5's database configuration? I haven't changed any of the defaults on either of the MySql 5.5 installations. I'm just using the standard MySql Connector/Net 6.5.4 to access the DB along with Microsoft's standard MVC 3, C#, Entity Framework 4, LINQ-to-Entities code.
Any help on this is greatly appreciated. Thanks, Atlas361
I published my MVC application to the ISP so that any potential issue caused by querying across the internet was eliminated but I still had the same exact error "Object must implement IConvertible”. After troubleshooting this further with the completely inept support staff at Arvixe.com I discovered that the actual version of MySql they had the database on was 5.1.54 released 2008 and not MySql 5.5 that was released in late 2010. According to the MySql documentation the MySql Connector/Net 6.5.4 & Microsoft's Entity Framework 4 are compatible, but I found this not to be true. After fighting with Arvixe.com to put me on MySql 5.5 server the problem went away. So in the end this was version compatibility issue.
Hope the answer helps! Atlas361