Diplom_O/DataBase/TypeStajDB.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Diplom_O.DataBase
{
  public class TypeStaj
  {
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }
    public string Name { get; set; }
		public List<CorrStaj> CorrStajy { get; set; }
		public List<RabotnikTypeStaj> RabotnikTypeStajy { get; set; }
	}

	public static partial class FuncDB
	{
		public static void TypeStajCheckValid(TypeStaj obj)
		{
			try
			{
				if (obj == null)
					throw new Exception("Ошибка инициализации стажа.");
				if (string.IsNullOrEmpty(obj.Name))
					throw new Exception("Пустой стаж.");
			}
			catch
			{
				throw;
			}
		}

		public static TypeStaj TypeStajGetById(int id)
		{
			try
			{
				using (var db = new MainDB())
				{
					var res =
						from a in db.TypeStajy
						where a.Id == id
						select a;
					try
					{
						return res.Single();
					}
					catch
					{
						return null;
					}
				}
			}
			catch
			{
				throw;
			}
		}
		public static TypeStaj TypeStajGetByName(string name)
		{
			try
			{
				using (var db = new MainDB())
				{
					var chkTypeStaj =
						from a in db.TypeStajy
						where a.Name == name
						select a;
					try
					{
						return chkTypeStaj.Single();
					}
					catch
					{
						return null;
					}
				}
			}
			catch
			{
				throw;
			}
		}

		public static void TypeStajAdd(TypeStaj obj)
		{
			try
			{
				TypeStajCheckValid(obj);
				if (TypeStajGetByName(obj.Name) != null)
					throw new Exception("Тип стажа существует.");
				using (var db = new MainDB())
				{
					db.TypeStajy.Add(obj);
					db.SaveChanges();
				}
			}
			catch
			{
				throw;
			}
		}
		public static void TypeStajChange(TypeStaj obj)
		{
			try
			{
				TypeStajCheckValid(obj);
				var localObjById = TypeStajGetById(obj.Id);
				var localObjByName = TypeStajGetByName(obj.Name);
				if (localObjById == null)
					throw new Exception("Тип стажа не существует.");
				if (localObjByName != null &&
					localObjByName != localObjById)
					throw new Exception("Тип стажа существует.");
				using (var db = new MainDB())
				{
					db.TypeStajy.Update(obj);
					db.SaveChanges();
				}
			}
			catch
			{
				throw;
			}
		}
		public static void TypeStajDelete(TypeStaj obj)
		{
			try
			{
				if (obj == null)
					return;
				var localObj = TypeStajGetById(obj.Id);
				if (localObj == null)
					throw new Exception("Тип стажа не существует.");
				if (RabotnikTypeStajListByTypeStaj(localObj.Id).Length > 0)
					throw new Exception("Тип стажа используется.");
				using (var db = new MainDB())
				{
					db.TypeStajy.Remove(localObj);
					db.SaveChanges();
				}
			}
			catch
			{
				throw;
			}
		}

		public static TypeStaj[] TypeStajList(int[] filter = null)
		{
			try
			{
				using (var db = new MainDB())
				{
					var res = (
						from a in db.TypeStajy
						where filter == null || filter.Contains(a.Id) 
						select a
						).ToList();
					return res.ToArray();
				}
			}
			catch
			{
				throw;
			}
		}
		public static string[] TypeStajListString(int[] filter = null)
		{
			try
			{
				using (var db = new MainDB())
				{
					var res = (
						from a in db.TypeStajy
						where filter == null || filter.Contains(a.Id)
						select a.Name
						).ToList();
					res.Remove("Общий");
					return res.ToArray();
				}
			}
			catch
			{
				throw;
			}
		}
	}


}