Ndtyjky

Exception Argument types do not match is thrown, although both of them are DateTime.
Exception is thrown at

CreatedAt = db.TransactionLogs

     .Last(x => x.TransactionId == a.Id)                                    

     .CreatedAt

Query works just fine if I put CreatedAt = DateTime.Now() instead

TransactionLogs.CreatedAt is not nullable and I don't understand what's the issue.

public IList<HeadlineDisplayModel> GetTeamApplicationHeadlines(string userId, int year)

        {

            using (var db = new TrainingManagerDbContext(Options))

            {

                return (from a in db.Transactions

                        join o in db.Options on a.OptionId equals o.Id

                        join e in db.Employees on a.EmployeeId equals e.Id

                        join s in db.TransactionStatuses on a.TransactionStatusId equals s.Id

                        where

                            a.Employee.DirectManagerId == userId

                            && a.TransactionStatus.Id != TransactionStatus.DRAFT

                            && !a.IsDeleted

                            && a.BudgetYear == year

                        select new HeadlineDisplayModel

                        {

                            Title = o.Title,

                            TransactionId = a.Id,

                            DateFrom = a.PeriodFrom,

                            Price = a.Price,

                            StatusName = s.Name,

                            EmployeeFullName = e.FullName,

                            CreatedAt = db.TransactionLogs.Last(x => x.TransactionId == a.Id)

                                .CreatedAt

                        }).OrderByDescending(x => x.CreatedAt).ToList();

            }

        }

HeadlineDisplayModel

public DateTime CreatedAt { get; set; }


TransactionLog

[Required]

[Column("created_at", TypeName = "datetime")]

public DateTime CreatedAt { get; set; }

    USE [KanbanBoard]

GO



/****** Object:  Table [tm].[TransactionLogs]    Script Date: 16.11.2018 14:49:57 ******/

SET ANSI_NULLS ON

GO



SET QUOTED_IDENTIFIER ON

GO



CREATE TABLE [tm].[TransactionLogs](

    [id] [int] IDENTITY(1,1) NOT NULL,

    [transaction_id] [int] NOT NULL,

    [price] [decimal](18, 2) NULL,

    [transaction_status_id] [varchar](8) NULL,

    [budget_year] [int] NULL,

    [additional_price] [decimal](18, 2) NOT NULL,

    [period_from] [datetime] NOT NULL,

    [period_to] [datetime] NOT NULL,

    [comment] [nvarchar](max) NULL,

    [created_by] [varchar](70) NULL,

    [created_at] [datetime] NOT NULL,

    [total_hours] [int] NOT NULL,

 CONSTRAINT [PK_TransactionLogs] PRIMARY KEY CLUSTERED 

(

    [id] ASC

)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

GO



ALTER TABLE [tm].[TransactionLogs] ADD  DEFAULT ((0)) FOR [total_hours]

GO



ALTER TABLE [tm].[TransactionLogs]  WITH CHECK ADD  CONSTRAINT [FK_TransactionLogs_Employees_created_by] FOREIGN KEY([created_by])

REFERENCES [tm].[Employees] ([id])

GO



ALTER TABLE [tm].[TransactionLogs] CHECK CONSTRAINT [FK_TransactionLogs_Employees_created_by]

GO



ALTER TABLE [tm].[TransactionLogs]  WITH CHECK ADD  CONSTRAINT [FK_TransactionLogs_Transactions_transaction_id] FOREIGN KEY([transaction_id])

REFERENCES [tm].[Transactions] ([id])

ON DELETE CASCADE

GO



ALTER TABLE [tm].[TransactionLogs] CHECK CONSTRAINT [FK_TransactionLogs_Transactions_transaction_id]

GO



ALTER TABLE [tm].[TransactionLogs]  WITH CHECK ADD  CONSTRAINT [FK_TransactionLogs_TransactionStatuses_transaction_status_id] FOREIGN KEY([transaction_status_id])

REFERENCES [tm].[TransactionStatuses] ([id])

GO



ALTER TABLE [tm].[TransactionLogs] CHECK CONSTRAINT [FK_TransactionLogs_TransactionStatuses_transaction_status_id]

GO

db.TransactionLogs.OrderByDescending(x=> x.Id)

       .First(x => x.TransactionId == a.Id)

       .CreatedAt

Something's wrong with Linq Last, so I ordered it in opposite and used First. Everything is okey now. :)