Question

I have a column in my table called AllowComent. This column has bit data type.

In my C# code I try recover the value

protected string RecoverAllowComent(string id)
{
    try
    {
        using(SqlConnection conexao = new SqlConnection(_conexao))
        {
            SqlCommand comando = new SqlCommand();
            comando.CommandText = "SELECT AllowComent FROM San_Blog WHERE Id = @Id";
            comando.Parameters.Add(new SqlParameter("@Id", id));
            comando.CommandType = CommandType.Text;
            comando.Connection = conexao;
            conexao.Open();
            comando.ExecuteNonQuery();

            SqlDataAdapter da = new SqlDataAdapter(comando);
            DataTable dt = new DataTable();
            da.Fill(dt);

            if (dt.Rows.Count > 0)
            {
                return dt.Rows[0].ItemArray[0].ToString();
            }
            else                    
                return "False";
         }
     }
     catch
     {
         return "False";
     }
}

But I got the error
Conversion failed when converting the nvarchar value ''1'' to data type int.

Answer 1

You are passing passing id which has type string. You need to pass int to parameter id.

Change

comando.Parameters.Add(new SqlParameter("@Id", id));

To

comando.Parameters.Add(new SqlParameter("@Id", int.Parse(id)));

If it is possible you can change type of your parameter ID of RecoverAllowComent to int to get away from type casting string to int.