Reverse engineering: Scaffold-DbContext can result in invalid SQL for computed column constraint

[pablotdv]

When I run the "Scaffold-DbContext" command on an existing database. I'm having problems with the calculated columns.

The script of my Table

CREATE TABLE [dbo].[Caixas](
	[CaixaId] [uniqueidentifier] NOT NULL,
	[Percentual] [decimal](18, 2) NOT NULL,
	[Quantidade] [decimal](18, 2) NOT NULL,
	[Valor] [decimal](18, 2) NOT NULL,
	[ValorDesconto]  AS (([Valor]*[Quantidade])/([Percentual]/(100))),
 CONSTRAINT [PK_Caixas] PRIMARY KEY CLUSTERED 
(
	[CaixaId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

After running the command

Scaffold-DbContext "Server=.\SQLExpress;Database=TestComputedColumn;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models2

My OnModelCreating was as follows:

protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Caixas>(entity =>
            {
                entity.HasKey(e => e.CaixaId)
                    .HasName("PK_Caixas");

                entity.Property(e => e.CaixaId).ValueGeneratedNever();

                entity.Property(e => e.Percentual).HasColumnType("decimal");

                entity.Property(e => e.Quantidade).HasColumnType("decimal");

                entity.Property(e => e.Valor).HasColumnType("decimal");

                entity.Property(e => e.ValorDesconto)
                    .HasColumnType("decimal")
                    .HasComputedColumnSql("[Valor]*[Quantidade])/([Percentual]/(100)")
                    .ValueGeneratedOnAddOrUpdate();
            });
        }

Note the attribute HasComputedColumnSql, where I have some missing parentheses.

The correct is HasComputedColumnSql("([Valor]*[Quantidade])/([Percentual]/(100)")

Further technical details

EF Core version: netcoreapp1.1
Database Provider: (e.g. Microsoft.EntityFrameworkCore.SqlServer)
Operating system:
IDE: (e.g. Visual Studio 2017)

[ajcvickers]

@lajones We may have some special handling for this in EF6; you might want to look at it for reference.

[pablotdv]

So I would have some tutorial explaining how I could do to debug the EF project code.

[ajcvickers]

@pablotdv I'm not sure exactly what you are asking, but if you mean building and working with the EF code yourself, then there some instructions here: https://github.com/aspnet/EntityFramework/wiki/Getting-and-Building-the-Code

[lajones]

Consider trimming the default value at the same time - see discussion in issue 8077

[lajones]

Note: we decided not to trim. In fact we are now not interpreting the value we get from the metadata at all - we just put it into the HasComputedColumnSql() method (this also applies to the HasDefaultValueSql() method) exactly as it comes from the DB.

[lajones]

Fixed by PR #8217.