C#•6mo ago

DateTime.UtcNow returns 0001-01-01T00:00:00

Hello guys I have BaseEntity and it has createdAt,modifiedAt values in it So the problem is when i run this code it returns

"createdAt": "2023-12-27T13:57:08.3933333",
    "modifiedAt": "0001-01-01T00:00:00"

"createdAt": "2023-12-27T13:57:08.3933333",
    "modifiedAt": "0001-01-01T00:00:00"

But i want the values to be same when it's first created

c#
public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
{
    DateTime now = DateTime.UtcNow;

    foreach (var entry in ChangeTracker.Entries<BaseEntity>())
    {
        switch (entry.State)
        {
            case EntityState.Added:
                if (entry.Entity.CreatedAt == DateTime.MinValue)
                {
                    entry.Entity.CreatedAt = now;
                }
                entry.Entity.ModifiedAt = now;
                break;

            case EntityState.Modified:
                entry.Entity.ModifiedAt = now;
                break;
        }
        Console.WriteLine($"Entity Type: {entry.Entity.GetType().Name}, State: {entry.State}, CreatedAt: {entry.Entity.CreatedAt}, ModifiedAt: {entry.Entity.ModifiedAt}");
    }

    return await base.SaveChangesAsync(cancellationToken);
}
}

c#
public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
{
    DateTime now = DateTime.UtcNow;

    foreach (var entry in ChangeTracker.Entries<BaseEntity>())
    {
        switch (entry.State)
        {
            case EntityState.Added:
                if (entry.Entity.CreatedAt == DateTime.MinValue)
                {
                    entry.Entity.CreatedAt = now;
                }
                entry.Entity.ModifiedAt = now;
                break;

            case EntityState.Modified:
                entry.Entity.ModifiedAt = now;
                break;
        }
        Console.WriteLine($"Entity Type: {entry.Entity.GetType().Name}, State: {entry.State}, CreatedAt: {entry.Entity.CreatedAt}, ModifiedAt: {entry.Entity.ModifiedAt}");
    }

    return await base.SaveChangesAsync(cancellationToken);
}
}

28 Replies

Pobiega•6mo ago

Seems like a faulty conclusion you are making there. Have you verified that the state truly is Added or Modified in the case above?

SogdianWarrior•6mo ago

Looks like DateTime.UtcNow isn't the issue, since it has already assigned its value to CreatedAt, but like obiega already mentioned, are you sure the state is trully Added or Modified? Because it's possible that the state is actually none of the two, and CreatedAt has been given a value somewhere else outside of this SaveChangesAsync function Can you show the piece of code where the SaveChangesAsync function is being called from? @baristaner

baristaner•6mo ago

Sure

c#
public async Task UpdateCode(int id, string newCode, bool isActive)
{
    var codeToUpdate = await _context.Codes.FindAsync(id);

    if (codeToUpdate != null)
    {
        codeToUpdate.Code = newCode;
        codeToUpdate.IsActive = isActive;
        //codeToUpdate.ModifiedAt = DateTime.UtcNow;

        await _context.SaveChangesAsync();
    }
}

c#
public async Task UpdateCode(int id, string newCode, bool isActive)
{
    var codeToUpdate = await _context.Codes.FindAsync(id);

    if (codeToUpdate != null)
    {
        codeToUpdate.Code = newCode;
        codeToUpdate.IsActive = isActive;
        //codeToUpdate.ModifiedAt = DateTime.UtcNow;

        await _context.SaveChangesAsync();
    }
}

So this has no issues But the problem is here

c#
public void GenerateCodes()
{
    _context.Database.ExecuteSqlRaw("EXEC dbo.GenerateCodes");
}

c#
public void GenerateCodes()
{
    _context.Database.ExecuteSqlRaw("EXEC dbo.GenerateCodes");
}

I've never called the function in here tho

Pobiega•6mo ago

well uh thats you activating a stored procedure via raw SQL

SogdianWarrior•6mo ago

Okay so, have you verified whether the state is either Added / Modified?

Pobiega•6mo ago

the changetracker is not aware of any changes done via rawsql or via stored procedures

SogdianWarrior•6mo ago

yeah it's a stored procedure, why should that even assign a value to modifiedAt from the code? unless you have a piece of SQL code that assigns a value to modifiedAt, but let's keep that aside Your question is about the UpdateCode function, updating values, and not seeing the expected value back in the database

baristaner•6mo ago

Stored Procedure does nothing to that entity it inserts values into Codes table And the BaseTable is basically just the default values like Id,createdAt,modifiedAt

"createdAt": "2023-12-27T13:57:08.3933333",
"modifiedAt": "0001-01-01T00:00:00"

"createdAt": "2023-12-27T13:57:08.3933333",
"modifiedAt": "0001-01-01T00:00:00"

createdAt is correct but modifiedAt is not it creates the timestamp perfectly except one thing. So when i run this procedure it will automatically create these fields

SogdianWarrior•6mo ago

have you debugged your code and checked the code step-by-step inside the savechangesasync? have you confirmed that the state is either added or modified?

baristaner•6mo ago

Trying that rn brb

SogdianWarrior•6mo ago

yes plz

baristaner•6mo ago

c#
Entity Type: Codes, State: Modified, CreatedAt: 12/27/2023 1:47:38 PM, ModifiedAt: 12/27/2023 11:23:03 AM

c#
Entity Type: Codes, State: Modified, CreatedAt: 12/27/2023 1:47:38 PM, ModifiedAt: 12/27/2023 11:23:03 AM

I just ran UpdateCode()

SogdianWarrior•6mo ago

okay, so it does assign a value to it and in the database?

baristaner•6mo ago

Yep But not when i run the stored Procedure

SogdianWarrior•6mo ago

well then i need to see your stored procedure sql statement

baristaner•6mo ago

Not the modifiedAt i mean

SogdianWarrior•6mo ago

if you could copy your sql statement here

baristaner•6mo ago

Sure mate

ALTER PROCEDURE [dbo].[GenerateCodes]
    @NumOfCodes INT = 50,
    @CharacterSet NVARCHAR(50) = '13456789ACDEFHKLMNPQRTVWXYZ',
    @ExpirationMonths INT = 3,
    @ExpirationDate DATE = NULL /* TIME FORMAT ; YYYY-MM-DD */
AS
BEGIN
    SET NOCOUNT ON;
    DECLARE @Counter INT = 1;

    BEGIN TRY
        BEGIN TRANSACTION;

        WHILE @Counter <= @NumOfCodes
        BEGIN
            DECLARE @RandomString VARCHAR(10);
            SET @ExpirationDate = DATEADD(MONTH, 3, GETDATE());
            SET @RandomString = '';

            DECLARE @InnerCounter INT = 1;
            WHILE @InnerCounter <= 10
            BEGIN
                SET @RandomString = @RandomString + SUBSTRING(@CharacterSet, (ABS(CHECKSUM(NEWID())) % LEN(@CharacterSet) + 1), 1);
                SET @InnerCounter = @InnerCounter + 1;
            END;

            INSERT INTO dbo.Codes (CODE, ExpirationDate,createdAt,IsActive)
            VALUES (@RandomString, @ExpirationDate,GETDATE(),1);

            SET @Counter = @Counter + 1;
        END;

        COMMIT TRANSACTION;
    END TRY
    BEGIN CATCH
        ROLLBACK TRANSACTION;

        PRINT 'An error occurred. Transaction rolled back.';
        PRINT ERROR_MESSAGE();
    END CATCH;
END;

ALTER PROCEDURE [dbo].[GenerateCodes]
    @NumOfCodes INT = 50,
    @CharacterSet NVARCHAR(50) = '13456789ACDEFHKLMNPQRTVWXYZ',
    @ExpirationMonths INT = 3,
    @ExpirationDate DATE = NULL /* TIME FORMAT ; YYYY-MM-DD */
AS
BEGIN
    SET NOCOUNT ON;
    DECLARE @Counter INT = 1;

    BEGIN TRY
        BEGIN TRANSACTION;

        WHILE @Counter <= @NumOfCodes
        BEGIN
            DECLARE @RandomString VARCHAR(10);
            SET @ExpirationDate = DATEADD(MONTH, 3, GETDATE());
            SET @RandomString = '';

            DECLARE @InnerCounter INT = 1;
            WHILE @InnerCounter <= 10
            BEGIN
                SET @RandomString = @RandomString + SUBSTRING(@CharacterSet, (ABS(CHECKSUM(NEWID())) % LEN(@CharacterSet) + 1), 1);
                SET @InnerCounter = @InnerCounter + 1;
            END;

            INSERT INTO dbo.Codes (CODE, ExpirationDate,createdAt,IsActive)
            VALUES (@RandomString, @ExpirationDate,GETDATE(),1);

            SET @Counter = @Counter + 1;
        END;

        COMMIT TRANSACTION;
    END TRY
    BEGIN CATCH
        ROLLBACK TRANSACTION;

        PRINT 'An error occurred. Transaction rolled back.';
        PRINT ERROR_MESSAGE();
    END CATCH;
END;

SogdianWarrior•6mo ago

ok lemme check

baristaner•6mo ago

My entities Code.cs

c#
using fastwin.Entities;
using System.ComponentModel.DataAnnotations;

namespace fastwin.Models
{
    public class Codes : BaseEntity
    {

        [StringLength(10)]
        public string? Code { get; set; }

        public DateTime? ExpirationDate { get; set; } 

        public bool IsActive { get; set; }
    }
}

c#
using fastwin.Entities;
using System.ComponentModel.DataAnnotations;

namespace fastwin.Models
{
    public class Codes : BaseEntity
    {

        [StringLength(10)]
        public string? Code { get; set; }

        public DateTime? ExpirationDate { get; set; } 

        public bool IsActive { get; set; }
    }
}

Base.cs

c#
using System.ComponentModel.DataAnnotations;

namespace fastwin.Entities
{
    public class BaseEntity
    {
        [Key]
        public int Id { get; set; }
        public DateTime CreatedAt { get; set; } 
        public DateTime ModifiedAt { get; set; }
    }
}

c#
using System.ComponentModel.DataAnnotations;

namespace fastwin.Entities
{
    public class BaseEntity
    {
        [Key]
        public int Id { get; set; }
        public DateTime CreatedAt { get; set; } 
        public DateTime ModifiedAt { get; set; }
    }
}

SogdianWarrior•6mo ago

INSERT INTO dbo.Codes (CODE, ExpirationDate,createdAt,IsActive) VALUES (@RandomString, @ExpirationDate,GETDATE(),1); you dont insert anything into the ModifiedAt column? I do see createdAt, but not modifiedAt

baristaner•6mo ago

oh yeah i totally forget about it

SogdianWarrior•6mo ago

ALTER PROCEDURE [dbo].[GenerateCodes]
    @NumOfCodes INT = 50,
    @CharacterSet NVARCHAR(50) = '13456789ACDEFHKLMNPQRTVWXYZ',
    @ExpirationMonths INT = 3,
    @ExpirationDate DATE = NULL /* TIME FORMAT ; YYYY-MM-DD */
AS
BEGIN
    SET NOCOUNT ON;
    DECLARE @Counter INT = 1;

    BEGIN TRY
        BEGIN TRANSACTION;

        WHILE @Counter <= @NumOfCodes
        BEGIN
            DECLARE @RandomString VARCHAR(10);
            SET @ExpirationDate = DATEADD(MONTH, 3, GETDATE());
            SET @RandomString = '';

            DECLARE @InnerCounter INT = 1;
            WHILE @InnerCounter <= 10
            BEGIN
                SET @RandomString = @RandomString + SUBSTRING(@CharacterSet, (ABS(CHECKSUM(NEWID())) % LEN(@CharacterSet) + 1), 1);
                SET @InnerCounter = @InnerCounter + 1;
            END;

            SET @UtcNow = GETUTCDATE();
            INSERT INTO dbo.Codes (CODE, ExpirationDate,CreatedAt,ModifiedAt,IsActive)
            VALUES (@RandomString, @ExpirationDate,@UtcNow,@UtcNow,1);

            SET @Counter = @Counter + 1;
        END;

        COMMIT TRANSACTION;
    END TRY
    BEGIN CATCH
        ROLLBACK TRANSACTION;

        PRINT 'An error occurred. Transaction rolled back.';
        PRINT ERROR_MESSAGE();
    END CATCH;
END;

something like this

baristaner•6mo ago

What if i call the function _context.SaveChangesAsync();

c#
 public void GenerateCodes()
 {
     _context.Database.ExecuteSqlRaw("EXEC dbo.GenerateCodes");
 }

c#
 public void GenerateCodes()
 {
     _context.Database.ExecuteSqlRaw("EXEC dbo.GenerateCodes");
 }

and remove those values in stored procedure?

SogdianWarrior•6mo ago

you can either do the code in C#, or you can let the stored procedure do it but the savechangesasync will handle the createdAt and modifiedAt

Pobiega•6mo ago

EF (where the context and SaveChanges comes from) isn't aware of any changes done by the stored procedure you either do this with EF, or you do it with the stored procedure. Not both.

SogdianWarrior•6mo ago

if that's what @baristaner is asking, then indeed EF isn't aware of the changes done by the stored procedure.

baristaner•6mo ago

Okay gotcha thanks guys I'm trying a different approach rn

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DateTime.UtcNow returns 0001-01-01T00:00:00