EntityFramework：使用视图来扩展表

Question

我想使用视图将信息添加到这样的表中

public class PocoTable
{
    public int Id { get; set; }
}

public partial class ImportStatingRecordError : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.Sql(@"
CREATE VIEW PocoView
AS
    SELECT Id, ISNULL(l.InterestingValue, '?') AS InterestingValue
    FROM PocoTable t
        LEFT JOIN OtherTable o ON t.Id = o.PocoTableId
");
    }
}

public class PocoView : PocoTable
{
    public string InterestingValue { get; set; }
}

public class ApplicationDbContext : DbContext
{
    public DbSet<PocoTable> PocoTables { get; set; }
    public DbSet<PocoView> PocoViews { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Entity<PocoView>().ToView("PocoView").HasKey(z => new z.Id);
    }
}

但 EntityFramework（核心）没有任何这些，因为：

实体类型“PocoView”无法映射到表，因为它是从“PocoTable”派生的。只有基本实体类型可以映射到表。

这可以发挥作用吗？或者我可以用其他方式做到这一点吗？

Answer 1

You can use HasBaseType(Type) method and pass null to let EF Core not treat PocoTable as base entity (part of database inheritance) of PocoView, e.g.

modelBuilder.Entity<PocoView>()
    .HasBaseType((Type)null) // <--
    .ToView("PocoView");