Validate that filters are the same for shared indexes

[ska737]

When using base class, attempting to be unique within the specific typed class does not apply the unique with Code-First.

Example excerpt:

public class TestContext : DbContext
{
  DbSet<ImplementClassOne> Ones { get; set; }
  DbSet<ImplementClassTwo> Twos { get; set; }

  protected void OnModelCreating(ModelBuilder builder)
  {
    modelBuilder.Entity<Base>().HasDiscriminator<string>("Type")
      .HasValue<ImplementClassOne>("one")
      .HasValue<ImplementClassTwo>("two");

    modelBuilder.Entity<Base>().Property(base => base.UniqueVal)
      .IsRequired();

    modelBuilder.Entity<Base>().Property(base => base.RequiredVal)
      .IsRequired();

    modelBuilder.Entity<ImplementClassOne>().HasIndex(one => one.UniqueVal)
      .IsUnique()
      .HasFilter("Type = 'one'");

    modelBuilder.Entity<ImplementClassTwo>().HasIndex(two => two.UniqueVal)
      .IsUnique()
      .HasFilter("Type = 'two'");
  }
}

This configuration creates the following Up() method in the Migration file, using Code-First:

protected override void Up(MigrationBuilder migrationBuilder)
{
  migrationBuilder.CreateTable(
    name: "Base",
    columns: table => new
    {
      Id = table.Column<int>(type: "int", nullable: false)
        .Annotation(...),
      UniqueVal = table.Column<string>(type: "nvarchar(max)", nullable: false,
      RequiredVal = table.Column<string>(type: "nvarchar(max)", nullable: false
    },
    constraints: table =>
    {
      table.PrimaryKey("PK_Base", x => x.Id);
    });

  migrationBuilder.CreateIndex(
    name: "IX_Base_UniqueVal_One",
    table: "Base",
    column: "UniqueVal",
    unique: true,
    filter: "Type = 'one'");
}

The second unique filtered index is missing. I can manually insert the index into the migration file. However, I am unable to test the second constraint when using normal unit testing methods, since unit tests normally do not use migrations.

Expected behavior would be for all unique filtered indexes be applied.

[ajcvickers]

/cc @AndriySvyryd to take a look

[AndriySvyryd]

This should throw, but we have a bug in model validation and it doesn't currently check filters.

To configure two indexes give them unique database names:

modelBuilder.Entity<ImplementClassOne>().HasIndex(one => one.UniqueVal)
    .HasDatabaseName("IX_One")
    .IsUnique()
    .HasFilter("Type = 'one'");

modelBuilder.Entity<ImplementClassTwo>().HasIndex(two => two.UniqueVal)
    .HasDatabaseName("IX_Two")
    .IsUnique()
    .HasFilter("Type = 'two'");

In some cases, like when you'd need an index on the base type and a separate one on the derived type you need to instead give them unique model names:

modelBuilder.Entity<Base>().HasIndex(@base => @base.UniqueVal, "IX_Base")
    .IsUnique()
    .HasFilter("Type = 'base'");

modelBuilder.Entity<ImplementClassTwo>().HasIndex(two => two.UniqueVal, "IX_Two")
    .IsUnique()
    .HasFilter("Type = 'two'");

[roji]

Poaching