@app.get("/pets/{pet_id}", response_model=PetOut)
async def read_pet(pet_id: int):
    user = UserDB(
        email="******@****.***",
        hashed_password="secrethashed",
    )
    pet = PetDB(name="Nibbler", owner=user)
    return pet


@app.get("/pets/", response_model=List[PetOut])
async def read_pets():
    user = UserDB(
        email="******@****.***",
        hashed_password="secrethashed",
    )

		t.Errorf("Table with escape character, got %v", r.Statement.SQL.String())
	}

	r = dryDB.Table("(?) as u, (?) as p", DB.Model(&User{}).Select("name"), DB.Model(&Pet{}).Select("name")).Find(&User{}).Statement

		t.Fatalf("errors happened when create: %v", err)
	}

	user.Pets = []*Pet{{Name: "pet1"}, {Name: "pet2"}}
	if err := DB.Save(&user).Error; err != nil {
		t.Fatalf("errors happened when update: %v", err)
	}

	var user2 User
	DB.Preload("Pets").Find(&user2, "id = ?", user.ID)
	CheckUser(t, user2, user)

	for _, pet := range user.Pets {
		pet.Name += "new"
	}

	if err := DB.Save(&user).Error; err != nil {

	"time"

	"gorm.io/gorm"
	"gorm.io/gorm/utils/tests"
)

type User struct {
	*gorm.Model
	Name      *string
	Age       *uint
	Birthday  *time.Time
	Account   *tests.Account
	Pets      []*tests.Pet
	Toys      []*tests.Toy `gorm:"polymorphic:Owner"`
	CompanyID *int
	Company   *tests.Company
	ManagerID *uint
	Manager   *User
	Team      []*User           `gorm:"foreignkey:ManagerID"`

			References: []Reference{{"ID", "User", "UserID", "Account", "", true}},
		},
		{
			Name: "Pets", Type: schema.HasMany, Schema: "User", FieldSchema: "Pet",
			References: []Reference{{"ID", "User", "UserID", "Pet", "", true}},
		},
		{
			Name: "Toys", Type: schema.HasMany, Schema: "User", FieldSchema: "Toy",
			Polymorphic: Polymorphic{ID: "OwnerID", Type: "OwnerType", Value: "users"},

	} else if debug == "false" {
		db.Logger = db.Logger.LogMode(logger.Silent)
	}

	return
}

func RunMigrations() {
	var err error
	allModels := []interface{}{&User{}, &Account{}, &Pet{}, &Company{}, &Toy{}, &Language{}, &Coupon{}, &CouponProduct{}, &Order{}, &Parent{}, &Child{}, &Tools{}}
	rand.Seed(time.Now().UnixNano())

	}

	DB.Where(&User{Name: "find or create embedded struct"}).Assign(User{Age: 44, Account: Account{Number: "1231231231"}, Pets: []*Pet{{Name: "first_or_create_pet1"}, {Name: "first_or_create_pet2"}}}).FirstOrCreate(&user8)
	if err := DB.Where("name = ?", "first_or_create_pet1").First(&Pet{}).Error; err != nil {
		t.Errorf("has many association should be saved")
	}

			}
			relationships.Relations[relation.Name] = relation
		}
	}
}

// User has many Toys, its `Polymorphic` is `Owner`, Pet has one Toy, its `Polymorphic` is `Owner`
//
//	type User struct {
//	  Toys []Toy `gorm:"polymorphic:Owner;"`
//	}
//	type Pet struct {
//	  Toy Toy `gorm:"polymorphic:Owner;"`
//	}
//	type Toy struct {
//	  OwnerID   int
//	  OwnerType string
//	}

⚠ ⚓ ⚙️ "🐜": "🎚-🔗 🗺" 🗃.

🐜 ✔️ 🧰 🗜 ("*🗺*") 🖖 *🎚* 📟 & 💽 🏓 ("*🔗*").

⏮️ 🐜, 👆 🛎 ✍ 🎓 👈 🎨 🏓 🗄 💽, 🔠 🔢 🎓 🎨 🏓, ⏮️ 📛 & 🆎.

🖼 🎓 `Pet` 💪 🎨 🗄 🏓 `pets`.

& 🔠 *👐* 🎚 👈 🎓 🎨 ⏭ 💽.

🖼 🎚 `orion_cat` (👐 `Pet`) 💪 ✔️ 🔢 `orion_cat.type`, 🏓 `type`. & 💲 👈 🔢 💪, ✅ `"cat"`.

👫 🐜 ✔️ 🧰 ⚒ 🔗 ⚖️ 🔗 🖖 🏓 ⚖️ 👨‍💼.

**FastAPI**可与任何数据库在任何样式的库中一起与 数据库进行通信。

一种常见的模式是使用“ORM”：对象关系映射。

ORM 具有在代码和数据库表（“*关系型”）中的**对象**之间转换（“*映射*”）的工具。

使用 ORM，您通常会在 SQL 数据库中创建一个代表映射的类，该类的每个属性代表一个列，具有名称和类型。

例如，一个类`Pet`可以表示一个 SQL 表`pets`。

该类的每个*实例对象都代表数据库中的一行数据。*

又例如，一个对象`orion_cat`（`Pet`的一个实例）可以有一个属性`orion_cat.type`, 对标数据库中的`type`列。并且该属性的值可以是其它，例如`"cat"`。

这些 ORM 还具有在表或实体之间建立关系的工具（比如创建多表关系）。

这样，您还可以拥有一个属性`orion_cat.owner`，它包含该宠物所有者的数据，这些数据取自另外一个表。