Entity Framework Mysql Slow Query - mysql

Question

In my database I have 3 main classes which are Breeders, Horses and Races. These 3 tables have many-to-many relationships. A breeder can have multiple horses and a horse can have multiple breeders. Also a horse can enter multiple races and a race can have multiple horses entered. Now I want to query a breeders race stats. Using entity framework I have this line of code:
var races = DbContext.HorseBreeders
.Where(w => w.BreederId == someint)
.SelectMany(s => s.Horse.Races)
.ToList();
and this code generates this mysql query:
SELECT `w.Horse.Races`.`Id`, `w.Horse.Races`.`FinishTime`, `w.Horse.Races`.`Horse_Id`, `w.Horse.Races`.`Race_Id`
FROM `HorseBreeders` AS `w`
INNER JOIN `Horses` AS `w.Horse` ON `w`.`HorseId` = `w.Horse`.`Id`
INNER JOIN `RaceEntries` AS `w.Horse.Races` ON `w.Horse`.`Id` = `w.Horse.Races`.`Horse_Id`
WHERE `w`.`BreederId` = someint
and this query takes around 30 seconds.
Breeders table has 13k records
Horses table has 60k records
HorseBreeders table has 40k records
Races table has 110k records
RaceEntries table has 960k records.
In Mssql this same structure with a similar query was taking less than a second. But in Mysql its taking too much time. What am I doing wrong?
DbContext Classes:
public class Breeder
{
public int Id { get; set; }
[StringLength(50)]
public string Name { get; set; }
public virtual ICollection<HorseBreeder> Horses { get; set; }
}
public class Horse
{
public int Id { get; set; }
[StringLength(50)]
public string Name { get; set; }
public int? Father_Id { get; set; }
public virtual Horse Father { get; set; }
public int? Mother_Id { get; set; }
public virtual Horse Mother { get; set; }
public string BirthPlace { get; set; }
public DateTime? BirthDate { get; set; }
public virtual ICollection<HorseBreeder> Breeders { get; set; }
public virtual ICollection<RaceEntry> Races { get; set; }
public virtual ICollection<Horse> FatherChilds { get; set; }
public virtual ICollection<Horse> MotherChilds { get; set; }
}
public class HorseBreeder
{
public int HorseId { get; set; }
public Horse Horse { get; set; }
public int BreederId { get; set; }
public Breeder Breeder { get; set; }
}
public class Race
{
public int Id { get; set; }
public DateTime Time { get; set; }
public string Name { get; set; }
public virtual ICollection<RaceEntry> Horses { get; set; }
}
public class RaceEntry
{
public int Id { get; set; }
public int Race_Id { get; set; }
public virtual Race Race { get; set; }
public int Horse_Id { get; set; }
public virtual Horse Horse { get; set; }
public short? FinishTime { get; set; }
}
DbContext OnModelCreating:
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
// Horse
builder.Entity<HorseBreeder>()
.HasKey(bc => new { bc.HorseId, bc.BreederId });
builder.Entity<HorseBreeder>()
.HasOne(bc => bc.Horse)
.WithMany(b => b.Breeders)
.HasForeignKey(bc => bc.HorseId);
builder.Entity<HorseBreeder>()
.HasOne(bc => bc.Breeder)
.WithMany(c => c.Horses)
.HasForeignKey(bc => bc.BreederId);
builder.Entity<Horse>()
.HasOne(p => p.Father)
.WithMany(p => p.FatherChilds)
.HasForeignKey(p => p.Father_Id);
builder.Entity<Horse>()
.HasOne(p => p.Mother)
.WithMany(p => p.MotherChilds)
.HasForeignKey(p => p.Mother_Id);
// RaceEntry
builder.Entity<RaceEntry>()
.HasOne(m => m.Race)
.WithMany(t => t.Horses)
.HasForeignKey(m => m.Race_Id);
builder.Entity<RaceEntry>()
.HasOne(m => m.Horse)
.WithMany(t => t.Races)
.HasForeignKey(m => m.Horse_Id);
}
Database create migration:
public partial class initial_create : Migration
{
protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.CreateTable(
name: "Breeders",
columns: table => new
{
Id = table.Column<int>(nullable: false)
.Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
Name = table.Column<string>(maxLength: 50, nullable: true)
},
constraints: table =>
{
table.PrimaryKey("PK_Breeders", x => x.Id);
});
migrationBuilder.CreateTable(
name: "Horses",
columns: table => new
{
Id = table.Column<int>(nullable: false)
.Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
Name = table.Column<string>(maxLength: 50, nullable: true),
Father_Id = table.Column<int>(nullable: true),
Mother_Id = table.Column<int>(nullable: true),
BirthPlace = table.Column<string>(nullable: true),
BirthDate = table.Column<DateTime>(nullable: true)
},
constraints: table =>
{
table.PrimaryKey("PK_Horses", x => x.Id);
table.ForeignKey(
name: "FK_Horses_Horses_Father_Id",
column: x => x.Father_Id,
principalTable: "Horses",
principalColumn: "Id",
onDelete: ReferentialAction.Restrict);
table.ForeignKey(
name: "FK_Horses_Horses_Mother_Id",
column: x => x.Mother_Id,
principalTable: "Horses",
principalColumn: "Id",
onDelete: ReferentialAction.Restrict);
});
migrationBuilder.CreateTable(
name: "Races",
columns: table => new
{
Id = table.Column<int>(nullable: false)
.Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
Time = table.Column<DateTime>(nullable: false),
Name = table.Column<string>(nullable: true)
},
constraints: table =>
{
table.PrimaryKey("PK_Races", x => x.Id);
});
migrationBuilder.CreateTable(
name: "HorseBreeders",
columns: table => new
{
HorseId = table.Column<int>(nullable: false),
BreederId = table.Column<int>(nullable: false)
},
constraints: table =>
{
table.PrimaryKey("PK_HorseBreeders", x => new { x.HorseId, x.BreederId });
table.ForeignKey(
name: "FK_HorseBreeders_Breeders_BreederId",
column: x => x.BreederId,
principalTable: "Breeders",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
table.ForeignKey(
name: "FK_HorseBreeders_Horses_HorseId",
column: x => x.HorseId,
principalTable: "Horses",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
});
migrationBuilder.CreateTable(
name: "RaceEntries",
columns: table => new
{
Id = table.Column<int>(nullable: false)
.Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),
Race_Id = table.Column<int>(nullable: false),
Horse_Id = table.Column<int>(nullable: false),
FinishTime = table.Column<short>(nullable: true)
},
constraints: table =>
{
table.PrimaryKey("PK_RaceEntries", x => x.Id);
table.ForeignKey(
name: "FK_RaceEntries_Horses_Horse_Id",
column: x => x.Horse_Id,
principalTable: "Horses",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
table.ForeignKey(
name: "FK_RaceEntries_Races_Race_Id",
column: x => x.Race_Id,
principalTable: "Races",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);
});
migrationBuilder.CreateIndex(
name: "IX_HorseBreeders_BreederId",
table: "HorseBreeders",
column: "BreederId");
migrationBuilder.CreateIndex(
name: "IX_Horses_Father_Id",
table: "Horses",
column: "Father_Id");
migrationBuilder.CreateIndex(
name: "IX_Horses_Mother_Id",
table: "Horses",
column: "Mother_Id");
migrationBuilder.CreateIndex(
name: "IX_RaceEntries_Horse_Id",
table: "RaceEntries",
column: "Horse_Id");
migrationBuilder.CreateIndex(
name: "IX_RaceEntries_Race_Id",
table: "RaceEntries",
column: "Race_Id");
}
protected override void Down(MigrationBuilder migrationBuilder)
{
migrationBuilder.DropTable(
name: "HorseBreeders");
migrationBuilder.DropTable(
name: "RaceEntries");
migrationBuilder.DropTable(
name: "Breeders");
migrationBuilder.DropTable(
name: "Horses");
migrationBuilder.DropTable(
name: "Races");
}
}