C#•4mo ago

EF Core how can I access temporal table PeriordStart value to use it for "last modified" information

From the docs: var validFrom = foo.Property<DateTime>("VALID_FROM").CurrentValue; This works and i get the correct DateTime for when the row was last modified. But this is not very nice to do. I would like to be able to access this VALID_FROM via foo.ModifiedUtc My temporal definiton

            builder
                .ToTable(
                    "FOO",
                    b => b.IsTemporal(
                        tableBuilder =>
                        {
                            tableBuilder.HasPeriodStart("VALID_FROM");
                            tableBuilder.HasPeriodEnd("VALID_TO");
                            tableBuilder.UseHistoryTable("FOO_HISTORU");
                        }));

            builder
                .ToTable(
                    "FOO",
                    b => b.IsTemporal(
                        tableBuilder =>
                        {
                            tableBuilder.HasPeriodStart("VALID_FROM");
                            tableBuilder.HasPeriodEnd("VALID_TO");
                            tableBuilder.UseHistoryTable("FOO_HISTORU");
                        }));

What i've tried: Decorate the ModifiedUtc property with a [DatabaseGenerated(DatabaseGeneratedOption.Computed)]

             builder
                .Property(cc => cc.ModifiedUtc)
                .HasColumnName("VALID_FROM")
                // Prevent EF from using this property in insert / update statements.
                .ValueGeneratedOnAddOrUpdate();

             builder
                .Property(cc => cc.ModifiedUtc)
                .HasColumnName("VALID_FROM")
                // Prevent EF from using this property in insert / update statements.
                .ValueGeneratedOnAddOrUpdate();

But this just ends in an exception: Microsoft.Data.SqlClient.SqlException : Invalid column name 'VALID_FROM1'. So EF seems to enumerate one of my mappings by adding a 1 after the column name.

1 Reply

nicke•4mo ago

If anyone ever runs into this. Here was the best solution: https://github.com/dotnet/efcore/issues/26463#issuecomment-1984046675

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EF Core how can I access temporal table PeriordStart value to use it for "last modified" information