No mapping exists from DbType System.Collections.ObjectModel.ReadOnlyCollection`1[System.Object] to a known SqlCeType.

Question

User1493762548 posted

hi anyone help me .there is error in line 90. the given code is the part of  addProducts.cshtml . after filling the  information in form when click next the error occur.

here is error :

Server Error in '/' Application.

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No mapping exists from DbType System.Collections.ObjectModel.ReadOnlyCollection`1[System.Object] to a known SqlCeType.

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.ArgumentException: No mapping exists from DbType System.Collections.ObjectModel.ReadOnlyCollection`1[System.Object] to a known SqlCeType.

Source Error: 

Line 88: Line 89: var insertCommand = "INSERT INTO Products (ProductTitle,ProductType, CategoryId,Details,ContactNo,CityId,CityName, ProductPrice,UserId,newFileName , UploadDate,status) Values(@0, @1, @2,@3,@4,@5,@6,@7,@8,@9,@10,@11)"; Line 90: db.Execute(insertCommand, ProductTitle,ProductType,CategoryId,Details,ContactNo,CityId,CityName, ProductPrice,UserId,newFileName,DateTime.Now,status); Line 91: Line 92: //--------------- ----------------------

Source File: c:\Users\fiaz ranjha\Documents\My Web Sites\Photo Gallery\AddProducts.cshtml    Line: 90 

Stack Trace: 

[ArgumentException: No mapping exists from DbType System.Collections.ObjectModel.ReadOnlyCollection`1[System.Object] to a known SqlCeType.] System.Data.SqlServerCe.SqlCeType.FromClrType(Object value) +300918 System.Data.SqlServerCe.SqlCeParameter.set_Value(Object value) +36 WebMatrix.Data.<>c__DisplayClass12.<AddParameters>b__11(Object o, Int32 index) +109 System.Linq.<SelectIterator>d__5`2.MoveNext() +187 WebMatrix.Data.Database.AddParameters(DbCommand command, Object[] args) +169 WebMatrix.Data.Database.Execute(String commandText, Object[] args) +102 ASP._Page_AddProducts_cshtml.Execute() in c:\Users\fiaz ranjha\Documents\My Web Sites\Photo Gallery\AddProducts.cshtml:90 System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +196 System.Web.WebPages.WebPage.ExecutePageHierarchy(IEnumerable`1 executors) +68 System.Web.WebPages.WebPage.ExecutePageHierarchy() +151 System.Web.WebPages.StartPage.RunPage() +19 System.Web.WebPages.StartPage.ExecutePageHierarchy() +62 System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +76 System.Web.WebPages.WebPageHttpHandler.ProcessRequestInternal(HttpContextBase httpContext) +114

 

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ProductTitle = Request.Form["ProductTitle"];
 
       CategoryId = Request.Form["categoryId"];
       
      Details = Request.Form["Details"];
      ContactNo=Request.Form["ContactNo"];
      ProductPrice = Request.Form["ProductPrice"];
      ProductType=Request.Form["ProductType"];
      CityId=Request.Form["cityId"];
      var sql="SELECT  CityName FROM City where CityId=@0";
      var CityName = db.Query(sql,CityId);
       
     
 
 
       
       var insertCommand = "INSERT INTO Products (ProductTitle,ProductType, CategoryId,Details,ContactNo,CityId,CityName, ProductPrice,UserId,newFileName , UploadDate,status) Values(@0, @1, @2,@3,@4,@5,@6,@7,@8,@9,@10,@11)";
       db.Execute(insertCommand, ProductTitle,ProductType,CategoryId,Details,ContactNo,CityId,CityName, ProductPrice,UserId,newFileName,DateTime.Now,status);
        
      

Answer 1

User379720387 posted

Are you column names correct for this table?

Answer 2

User1493762548 posted

yes columns are correct . if i remove CityName from insertCommand   and db.execute  command  lines and remove the

var sql="SELECT CityName FROM City where CityId=@0";

var CityName = db.Query(sql,CityId);

the code works correctly

there is error in this section of code.

CityId=Request.Form["cityId"];

      var sql="SELECT  CityName FROM City where CityId=@0";
      var CityName = db.Query(sql,CityId);
       

Answer 3

User1493762548 posted

if i replace the said code with :

CityId=Request.Form["CityId"];
     
     var c = db.QuerySingle("SELECT CityName FROM City where CityId=@0,CityId");
       var CityName =c.CityName;
     

the error is :

very very thanks for your patience and response .

There was an error parsing the query. [ Token line number = 1,Token line offset = 42,Token in error = , ]

error on the line below:

var c = db.QuerySingle("SELECT CityName FROM City where CityId=@0,CityId");

Please Note: in the submitted form  input field has name="CityId"

Answer 4

User1493762548 posted

hi all, issue solved and worked well by replacing the above code with :

var p = db.QuerySingle("SELECT * FROM City WHERE CityId = @0", CityId);
       var CityName =p.CityName;

can anyone tell what the reason was? because it can help others .

lot of thanks .how helpful people you are? i am happy with you all.

Answer 5

User379720387 posted

db.Query gives a set of records

db.QuerySingle gives a single record

db.QueryValue gives a column from a single record

The helper knows what the result is (records, record, value) and if the query type doesn't match it throws all sorts of errors that don't seem to make much sense