CODEWITHSUNDEEP
c#.net-corerazor-pagesinner-exception
Gh17
Gh17

Reputation: 76

InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Int32'

I am trying to display the result from the database to the user on the front end but I keep getting the following exception:

InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Int32'

and

System.InvalidOperationException: 'An exception occurred while reading a database value for property 'CList.CourseCategory'. The expected type was 'LearnAngebot.Models.Courscategory' but the actual value was of type 'System.String'.'

I am lost as to what has gone wrong.

I have a similar code to display the courses and it seems to be working fine. I used the same format for this but keep getting this error.

The C# code:

public class IndexModel : PageModel
{
    public CUser User { get; set; }
    public bool empty { get; set; }

    public readonly IHostingEnvironment _env;
    private readonly CDataContext _context;
    private readonly IUserService _UserService;

    public IndexModel(CFE_CrazyLabContext context, IUserService UserService, IHostingEnvironment hostingEnvironment)
    {
        _env = hostingEnvironment;
        _context = context;
        _UserService = UserService;
        User = UserService.GetUser();
    }

    public IList<CList> ResultList { get; set; }
    public CUser StudentUser { get; set; }
    public CStudent Student { get; set; }

    public void LoadList(CList list)
    {
        StudentUser = _UserService.GetUser(list.StudentUser);
    }
    public void OnGet()
    {
        ResultList = _context.Result.Where(o => EF.Functions.Like(o.StudentUser, User.UserName)).ToList();

    }
}

HTML code:

@if(Model.ResultList.Count == 0)
{
<div>
    <h2> No Result yet </h2>
</div>
}

@if(Model.ResultList.Count > 0)
{
    <div class="Custom-Table Custom-Table-Big">
    <table>
        <tbody>
            <tr id="head">
                <th><a href="index.pgp?">Student UserName</a></th>

                <th><a href="index.php?">Course Name</a></th>

                <th><a href="index.pgp?">Category</a></th>

                <th><a href="index.pgp?">Date</a></th>
            </tr>

            @foreach(var item in Model.ResultList)
            {
                Model.LoadList(item);
                <tr>
                    <td>
                        @item.StudentUser
                    </td>

                    <td>
                        @item.CourseName
                    </td>

                    <td>
                        @item.CourseCategory
                    </td>

                    <td>
                        @item.Date
                    </td>
                </tr>
            }
        </tbody>
    </table>
</div>
}

Why exactly am i getting this exception and how do I resolve it? Thanks in advance.

Upvotes: 1

Views: 9016

Answers (2)

HorlaCode
HorlaCode

Reputation: 1

InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Int32': This error emerges from an error in your datatype of one of the column/Field in your table(model)

I will advise you to look at your model very well and make sure the type of datatype you are using to save your data because the system will not pinned point the specific field or column for you.

Upvotes: 0

Vikas Srivastava
Vikas Srivastava

Reputation: 21

Please check database Date Datatype and Model Date datatype and match together. If you getting error in any other property please debug using F11 and match from database datatype and model datatype.

Upvotes: 2

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