实体框架-不支持“ ColumnName”列的类型。 类型是“对象”

Question

I wrote a piece of code 6 months ago, which worked fine and was deployed in multiple environments. I have got a new enhancement now and when I try to run the same code, it strangely gives me an error. I search online but nothing much helpful. Below is the code in concern:

var parameter = new SqlParameter("@SearchCriteria", SqlDbType.Structured);
parameter.Value = searchCriteria;
parameter.TypeName = "dbo.SearchCriteria";

var output = entities.Database.SqlQuery<tablename>(
    "dbo.storedprocedureName @SearchCriteria", 
    parameter).ToList<tablename>();

It gives me the error

The type of column 'SelectedValue' is not supported. The type is 'Object'.

The same deployed code is still in running on other servers without any issues. Not sure what changed in my pc!!

My Table type definition:

    CREATE TYPE [dbo].[SearchCriteria] AS TABLE(
    [SelectedAttribute] [varchar](50) NULL,
    [SelectedCriteria] [varchar](50) NULL,
    [SelectedValue] [varchar](50) NULL)

I believe this error is not coming out of stored procedure but coming in ADO.NET / Entity Framework even before calling up the stored procedure. I kept a trace using SQL Profile so the call did never hit DB. I tried to run SP directly on SSMS and SP is working fine. So, I could see it is something to with either Entity Framework or ADO.NET.

Answer 1

I had an object in C# which stores SearchCriteria and gets converted to DataTable before being sent to Stored Procedure using EF.

One of the fields "SelectedValue" was declared as "Object". I changed that to "string" and everything is working fine.

I have absolutely no idea how this code has been working so far and why it broke now!! I was the one who wrote it and I'm the who modified it now so no middle person changes as well :)

Old Class:

public class SelectionCriteria
{
    public string SelectedAttribute { get; set; }
    public string SelectedCriteria { get; set; }
    public object SelectedValue { get; set; }
}

Modified Class:

public class SelectionCriteria
    {
        public string SelectedAttribute { get; set; }
        public string SelectedCriteria { get; set; }
        public string SelectedValue { get; set; }
    }