Ошибка заданное приведение является недопустимым

Note: I am looking for why this is happening and how to fix it, I am not looking for a workaround. This appears to be a server(SQL Server or Connection string) issue.

I have a program that is connected to a sql 2008 database (Database A) and I have inline sql that runs that has ints and strings returned and it works fine. But I have been asked to switch to another 2008 database (Database B) and now everything is coming back as a string and I am getting a specified cast is not valid from C# where when I am connected to the sql 2008 (Database A) it does not say this. This is a inline sql statement so the sql statement is not changing and the table schema of the database is the same. Its doing this on int primary keys Anyone have any ideas?

I originally thought the was a 2000 to 2008 issue but I now have the some problem on 2008 as well. Both databases are on the same instance of sql server these are the connection strings

Connection Strings

  Server=Server01instance;Database=Fraud_Micah; Trusted_Connection=yes <- Server 2008 (this one does not)
  Server=Server02instance;Database=Fraud; Trusted_Connection=yes <- Server 2008 (this one works)

Both databases are at DB compatibility_level of 100

The select Statement

select *, delimeter, file_filetype.LocalPath, ArchiveDir, EmailList
from file_importtable 
join file_filetype on file_importtable.FileTypeID = file_filetype.ID
where importsuccessdate is null and transferdate is not null
and remotediscoverdate is not null 
and OriginalFileName in ('Test987.xml.pgp')

fileTypeID is where its breaking -> InvalidCastException: Specified cast is not valid.

C# Code (Note reader is type SQLDataReader)

if (!(reader.IsDBNull(reader.GetOrdinal("FileTypeID"))))
{
    file.FileTypeID = reader.GetInt32(reader.GetOrdinal("FileTypeID"));
}

Here is the column definition: [FileTypeID] [int] NULL, there is no null values in the table.

I don’t think the C# code comes from this, its a int? public int? FileTypeID { get; set; }

In debug mode: reader["FileTypeID"] -> «1» it is in fact a string but why when I connect to a 2008 database would it return a 1 instaed of a «1»

2008 Table A Def

[ProcessSuccessDate] [datetime] NULL,
[ProcessSuccessUser] [datetime] NULL,
[FileTypeID] [int] NULL,
[HoldDate] [datetime] NULL,

2008 Table B Def

ProcessSuccessDate] [datetime] NULL,
[ProcessSuccessUser] [datetime] NULL,
[FileTypeID] [int] NULL,
[HoldDate] [datetime] NULL,

file.FileTypeID = (int)reader["FileTypeID"]; yields the same result.

Doing a

     file.FileTypeID (int)reader.GetInt32(reader.GetOrdinal("FileTypeID"));

does work but I don’t want to do that for every column that already should be coming back as a int also writing sql like this

     select Convert(int, FileTypeID) as FileTypeId, delimeter, file_filetype.LocalPath, ArchiveDir, EmailList

can get around the issue as well, however I want to know why I have to do this if I already set the type as a int in the table. I might as well put all the types as strings in the table. At this point I am not looking for a workaround I want to understand why its not working like it should be.

Нужна помощь. Есть база данных в microsoft sql server. Я хочу чтоб таблица отобразилась на windows форме с помощью datagridview. Но при запуске появляется ошибка (в заголовке).

public partial class Form1 : Form
{
    DataBase dataBase = new DataBase();
    public Form1()
    {
        InitializeComponent();

    }

    private void CreateColumns()
    {
        dataGridView1.Columns.Add("adr_id", "id");
        dataGridView1.Columns.Add("name", "Iм'я");
        dataGridView1.Columns.Add("bday", "День народження");
        dataGridView1.Columns.Add("address", "Адреса");
        dataGridView1.Columns.Add("tel", "Телефон");
        dataGridView1.Columns.Add("IsNew", String.Empty);
    }

    private void ReadSingleRow(DataGridView dgw, IDataRecord record)
    {
        dgw.Rows.Add(record.GetInt32(0), record.GetString(1), record.GetDateTime(2), record.GetString(3), record.GetInt32(4), RowState.ModifiedNew);
    }

    private void RefreshDataGrid(DataGridView dgw)
    {
        dgw.Rows.Clear();
        string queryString = $"select * from addressee";
        SqlCommand command = new SqlCommand(queryString, dataBase.GetConnection());
        dataBase.openConnection();
        SqlDataReader reader = command.ExecuteReader();
        while (reader.Read())
        {
            ReadSingleRow(dgw, reader);
        }
        reader.Close();

    }

    private void label1_Click(object sender, EventArgs e)
    {

    }

    private void label2_Click(object sender, EventArgs e)
    {

    }

    private void label_bday_Click(object sender, EventArgs e)
    {

    }

    private void Form1_Load(object sender, EventArgs e)
    {
        CreateColumns();
        RefreshDataGrid(dataGridView1);
    }
}

Здравствуйте. Создал класс представляющий таблицу в SQL —  tbl_Invoce

// Накладная
    [Table(Name= "tbl_Invoce")]
    public class CInvoce 
    {
        [Column(IsPrimaryKey = true, IsDbGenerated = true)] 
        // Номер документа
        public int DocumentId { set; get; } // 

        // Товар
        [Column]
        public string MaterialId{ set; get; }

        // Количество
        [Column]
        public int Quantity{ set; get; }

        // Цена
        [Column]
        public decimal Price{ set; get; }

        // Дата 
        [Column]
        public DateTime Date{ set; get; }

        // Ответственный 
        [Column]
        public string Accountable{ set; get; }


         private EntityRef<CMaterial> m;// = new EntityRef<CMaterial>();
        [Association(Storage = "m", ThisKey="MaterialId", OtherKey = "ID")]
        public CMaterial M
        {
            get {return m.Entity ;}
            set { m.Entity = value;}
        }

        
        // список накладных
        List<CInvoce> invoce = new List<CInvoce>();

        // Добавление накладной
        public void AddInvoce(CInvoce invoce)
        {
            
            // CMaterial material = 

        }

    }

Необходимо заполнить datagridView значениями  из этой таблицы. Вот  метод реализующий необходимое:

private void RefreshGridViewInvoce()
        {
//1)
             //List<CInvoce> invoces = dc.GetTable<CInvoce>().ToList();
            //dgvColInvoce.DataSource = invoces;

//2)
           Table<CInvoce> table= dc.GetTable<CInvoce>();
            dgvColInvoce.DataSource = table;
        }

Как первым, так и вторым способом выводиться ошибка InvalidCastException «Заданное приведение является недопустимым.»

Скажите, пожалуйста, в чем причина ошибки и как нужно исправить код.

Вот проект таблицы в SQL-сервере