EF Core 3.1 Beta OracleException: ORA-01460 — oracle-tech

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EF Core 3.1 Beta OracleException: ORA-01460

user606112
user606112 Member Posts: 9
edited July 2020 in ODP.NET

Adding an image and saving the context ORA-01460 occurs.

DB-Set in Model:

    public class Picture

    {

        public int PictureID { get; set; }

        public byte[] Bild { get; set; }

        public DateTime Ludsys { get; set; }

        public int OrderDetailID { get; set; }

        public OrderDetail OrderDetail { get; set; } // Navigationseigenschaft

    } // Picture

Table in DB:

Table in ORA DB.JPG

If I load the image and save it with SQL-Developer it can be read and displayed in the application.

Create the picture:

...

picture = new Picture

{

     Bild = null,

     Ludsys = DateTime.Now,

     OrderDetail = orderdetail

}; // picture

imgBild.DataContext = picture;

imgBild.Source = FileToBitmapImage(dlg.FileName); // Bild aus Filesystem laden und anzeigen

context.Pictures.Add(picture);

pictures.Add(picture);

ind = pictures.Count - 1; // Index für den neuen Datensatz ist pictures.Count - 1

...

        private BitmapImage FileToBitmapImage(string source)

        {

            try

            {

                if (source == string.Empty) { return null; }

                BitmapImage bitmapimage = new BitmapImage();

                using FileStream filestream = File.Open(source, FileMode.Open);

                bitmapimage.BeginInit();

                bitmapimage.CacheOption = BitmapCacheOption.OnLoad;

                bitmapimage.StreamSource = filestream;

                bitmapimage.EndInit();

                return bitmapimage;

            } // try

            catch (Exception ex)

            {

                MessageBox.Show(ex.Message, "Nachricht", MessageBoxButton.OK, MessageBoxImage.Error);

                return null;

            } // catch

        } // FileToBitmapImage

ImageConverter:

         public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)

        {

            try

            {

                if (value == null) { return null; }

                byte[] byteArray = (byte[])value;

                using MemoryStream memorystream = new MemoryStream(byteArray);

                BitmapImage bitmapimage = new BitmapImage();

                bitmapimage.BeginInit();

                bitmapimage.CacheOption = BitmapCacheOption.OnLoad;

                bitmapimage.StreamSource = memorystream;

                bitmapimage.EndInit();

                return bitmapimage;

            } // try

            catch (Exception)

            {

                return null;

            } // catch

        } // Convert

        // ConvertBack (Ziel -> Quelle)

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)

        {

            try

            {

                if (value == null) { return null; }

                ImageSource imagesource = (ImageSource)value;

                BitmapSource bitmapsource = imagesource as BitmapSource;

                BitmapEncoder encoder = new JpegBitmapEncoder();

                encoder.Frames.Add(BitmapFrame.Create(bitmapsource));

                using MemoryStream ms = new MemoryStream();

                encoder.Save(ms);

                byte[] bytearray = ms.ToArray();

                return bytearray;

            } // try

            catch (Exception)

            {

                return null;

            } // catch

        } // ConvertBack

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Best Answer

  • Alex Keh-Oracle
    Alex Keh-Oracle Posts: 2,751 Employee
    edited July 2020 Accepted Answer

    Have you tried the HasMaxLength on the Bild property, not the ProductName?

    modelBuilder.Entity<Picture>().Property(p => p.Bild).HasMaxLength(6000000);

    It should work with the HasMaxLength, but without the HasColumnType.

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Answers

  • Alex Keh-Oracle
    Alex Keh-Oracle Posts: 2,751 Employee
    edited July 2020

    Did you add the required Fluent API (i.e. HasMaxLength(x > 2000)) so that ODP.NET EF Core can map a byte[] to a BLOB?

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  • user606112
    user606112 Member Posts: 9
    edited July 2020

    My fluent API looks like this:

            protected override void OnModelCreating(ModelBuilder modelBuilder)

            {

                //Default - Schema: HR

                modelBuilder.HasDefaultSchema("HR");

                // Customer-Configuration

                modelBuilder.Entity<Customer>().Property(c => c.CompanyName).HasColumnType("varchar2");

                modelBuilder.Entity<Customer>().Property(c => c.CompanyName).HasMaxLength(40);

                modelBuilder.Entity<Customer>().Property(c => c.Ludsys).IsConcurrencyToken();

                // Order-Configuration

                modelBuilder.Entity<Order>().Property(o => o.Ludsys).IsConcurrencyToken();

                // OrderDetail-Configuration

                modelBuilder.Entity<OrderDetail>().Property(od => od.Ludsys).IsConcurrencyToken();

                // Product-Configuration

                modelBuilder.Entity<Product>().Property(p => p.ProductName).HasColumnType("varchar2");

                modelBuilder.Entity<Product>().Property(p => p.ProductName).HasMaxLength(40);

                modelBuilder.Entity<Product>().Property(p => p.Ludsys).IsConcurrencyToken();

                // Picture-Configuration

                modelBuilder.Entity<Picture>().Property(p => p.Bild).HasColumnType("blob");

                modelBuilder.Entity<Product>().Property(p => p.ProductName).HasMaxLength(6000000); // 6MB

                modelBuilder.Entity<Picture>().Property(p => p.Ludsys).IsConcurrencyToken();

                // Beziehungen der DbSets untereinander

                modelBuilder.Entity<Customer>().HasMany(c => c.Orders).WithOne(o => o.Customer);

                modelBuilder.Entity<Order>().HasMany(o => o.OrderDetails).WithOne(od => od.Order);

                modelBuilder.Entity<OrderDetail>().HasMany(od => od.Pictures).WithOne(p => p.OrderDetail);

                modelBuilder.Entity<Product>().HasMany(p => p.OrderDetails).WithOne(od => od.Product);

            } // OnModelCreating

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  • Alex Keh-Oracle
    Alex Keh-Oracle Posts: 2,751 Employee
    edited July 2020

    Have you tried adding the required HasMaxLength(x > 2000) Fluent API to the following line:

           modelBuilder.Entity<Picture>().Property(p => p.Bild).HasColumnType("blob");

    This Fluent API is required as per the documentation.

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  • user606112
    user606112 Member Posts: 9
    edited July 2020

    I tried 3 variants:

    only: modelBuilder.Entity<Picture>().Property(p => p.Bild).HasColumnType("blob");

               

    only: modelBuilder.Entity<Product>().Property(p => p.ProductName).HasMaxLength(6000000); // 6MB

    both: modelBuilder.Entity<Picture>().Property(p => p.Bild).HasColumnType("blob");

             modelBuilder.Entity<Product>().Property(p => p.ProductName).HasMaxLength(6000000); // 6MB

    I get always: ORA-01460

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  • Alex Keh-Oracle
    Alex Keh-Oracle Posts: 2,751 Employee
    edited July 2020 Accepted Answer

    Have you tried the HasMaxLength on the Bild property, not the ProductName?

    modelBuilder.Entity<Picture>().Property(p => p.Bild).HasMaxLength(6000000);

    It should work with the HasMaxLength, but without the HasColumnType.

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  • user606112
    user606112 Member Posts: 9
    edited July 2020

    Hallo Alex,

    thank you very much for your help. Only the following property is necessary.

    modelBuilder.Entity<Picture>().Property(p => p.Bild).HasMaxLength(6000000);

    I did much copy and paste to resolve the problem, so that I didn't see the wrong columnname "productname".

    Now all is working pretty .

    With kind regards! Günter Hoormann

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  • Alex Keh-Oracle
    Alex Keh-Oracle Posts: 2,751 Employee
    edited July 2020

    Hi Gunter,

    Glad to hear it works for you. Which DB version are you using?

    My team hadn't seen this error before when we tested similar scenarios.

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  • user606112
    user606112 Member Posts: 9
    edited July 2020

    Hallo Alex,

    I use DB-Version as below to create my Test-DB:

    BANNER                                                             

    -------------------------------------------------------------------

    Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production

    BANNER_FULL

    -------------------------------------------------------------------

    Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production

    Version 18.4.0.0.0

    BANNER_LEGACY

    -------------------------------------------------------------------

    Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production

    I created the DB by application in VisualStudio 2019 using the following nuget-packages:

    Util1.JPG

    DB looks like this:

    Util3.JPG

    Util4.JPG

    I tested EF Core 3.1 using packages:

    Util2.JPG

    Actual Fluent-API:

            protected override void OnModelCreating(ModelBuilder modelBuilder)

            {

                //Default - Schema: HR

                modelBuilder.HasDefaultSchema("HR");

                // Customer-Configuration

                modelBuilder.Entity<Customer>().Property(c => c.CompanyName).HasMaxLength(40);

                modelBuilder.Entity<Customer>().Property(c => c.Ludsys).IsConcurrencyToken();

                // Order-Configuration

                modelBuilder.Entity<Order>().Property(o => o.Ludsys).IsConcurrencyToken();

                // OrderDetail-Configuration

                modelBuilder.Entity<OrderDetail>().Property(od => od.Ludsys).IsConcurrencyToken();

                // Product-Configuration

                modelBuilder.Entity<Product>().Property(p => p.ProductName).HasMaxLength(40);

                modelBuilder.Entity<Product>().Property(p => p.Ludsys).IsConcurrencyToken();

                //Picture - Configuration

                modelBuilder.Entity<Picture>().Property(p => p.Bild).HasMaxLength(6000000); // 6MB

                modelBuilder.Entity<Picture>().Property(p => p.Ludsys).IsConcurrencyToken();

                // Beziehungen der DbSets untereinander

                modelBuilder.Entity<Customer>().HasMany(c => c.Orders).WithOne(o => o.Customer);

                modelBuilder.Entity<Order>().HasMany(o => o.OrderDetails).WithOne(od => od.Order);

                modelBuilder.Entity<OrderDetail>().HasMany(od => od.Pictures).WithOne(p => p.OrderDetail);

                modelBuilder.Entity<Product>().HasMany(p => p.OrderDetails).WithOne(od => od.Product);

            } // OnModelCreating

    For ludsys column I created some trigger like this:

    -- Customers

    create or replace trigger trg_Customers_Ludsys

      before insert or update on "Customers"

      for each row

    begin

      :new."Ludsys" := sysdate;

    end trg_Customers_Ludsys;

    /

    I hope this will help you.

    Günter

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