TypeScript
从 v5 开始,Sequelize 提供了自己的 TypeScript 定义. 请注意,仅支持 TS >= 3.1.
由于 Sequelize 严重依赖于运行时属性分配,因此 TypeScript 在开箱即用时不会很有用. 为了使模型可用,需要大量的手动类型声明.
安装
为了避免非 TS 用户的安装膨胀,你必须手动安装以下键入程序包:
@types/node(在 node 项目中这是通常是必须的)@types/validator
使用
带有严格类型检查的最小 TypeScript 项目示例.
import {
Sequelize,
Model,
DataTypes,
HasManyGetAssociationsMixin,
HasManyAddAssociationMixin,
HasManyHasAssociationMixin,
Association,
HasManyCountAssociationsMixin,
HasManyCreateAssociationMixin,
Optional,
} from 'sequelize';
const sequelize = new Sequelize('mysql://root:asd123@localhost:3306/mydb');
// These are all the attributes in the User model
interface UserAttributes {
id: number;
name: string;
preferredName: string | null;
}
// Some attributes are optional in `User.build` and `User.create` calls
interface UserCreationAttributes extends Optional<UserAttributes, 'id'> {}
class User extends Model<UserAttributes, UserCreationAttributes>
implements UserAttributes {
public id!: number; // Note that the `null assertion` `!` is required in strict mode.
public name!: string;
public preferredName!: string | null; // for nullable fields
// timestamps!
public readonly createdAt!: Date;
public readonly updatedAt!: Date;
// Since TS cannot determine model association at compile time
// we have to declare them here purely virtually
// these will not exist until `Model.init` was called.
public getProjects!: HasManyGetAssociationsMixin<Project>; // Note the null assertions!
public addProject!: HasManyAddAssociationMixin<Project, number>;
public hasProject!: HasManyHasAssociationMixin<Project, number>;
public countProjects!: HasManyCountAssociationsMixin;
public createProject!: HasManyCreateAssociationMixin<Project>;
// You can also pre-declare possible inclusions, these will only be populated if you
// actively include a relation.
public readonly projects?: Project[]; // Note this is optional since it's only populated when explicitly requested in code
public static associations: {
projects: Association<User, Project>;
};
}
interface ProjectAttributes {
id: number;
ownerId: number;
name: string;
}
interface ProjectCreationAttributes extends Optional<ProjectAttributes, 'id'> {}
class Project extends Model<ProjectAttributes, ProjectCreationAttributes>
implements ProjectAttributes {
public id!: number;
public ownerId!: number;
public name!: string;
public readonly createdAt!: Date;
public readonly updatedAt!: Date;
}
interface AddressAttributes {
userId: number;
address: string;
}
// You can write `extends Model<AddressAttributes, AddressAttributes>` instead,
// but that will do the exact same thing as below
class Address extends Model<AddressAttributes> implements AddressAttributes {
public userId!: number;
public address!: string;
public readonly createdAt!: Date;
public readonly updatedAt!: Date;
}
Project.init(
{
id: {
type: DataTypes.INTEGER.UNSIGNED,
autoIncrement: true,
primaryKey: true,
},
ownerId: {
type: DataTypes.INTEGER.UNSIGNED,
allowNull: false,
},
name: {
type: new DataTypes.STRING(128),
allowNull: false,
},
},
{
sequelize,
tableName: 'projects',
},
);
User.init(
{
id: {
type: DataTypes.INTEGER.UNSIGNED,
autoIncrement: true,
primaryKey: true,
},
name: {
type: new DataTypes.STRING(128),
allowNull: false,
},
preferredName: {
type: new DataTypes.STRING(128),
allowNull: true,
},
},
{
tableName: 'users',
sequelize, // passing the `sequelize` instance is required
},
);
Address.init(
{
userId: {
type: DataTypes.INTEGER.UNSIGNED,
},
address: {
type: new DataTypes.STRING(128),
allowNull: false,
},
},
{
tableName: 'address',
sequelize, // passing the `sequelize` instance is required
},
);
// Here we associate which actually populates out pre-declared `association` static and other methods.
User.hasMany(Project, {
sourceKey: 'id',
foreignKey: 'ownerId',
as: 'projects', // this determines the name in `associations`!
});
Address.belongsTo(User, { targetKey: 'id' });
User.hasOne(Address, { sourceKey: 'id' });
async function doStuffWithUser() {
const newUser = await User.create({
name: 'Johnny',
preferredName: 'John',
});
console.log(newUser.id, newUser.name, newUser.preferredName);
const project = await newUser.createProject({
name: 'first!',
});
const ourUser = await User.findByPk(1, {
include: [User.associations.projects],
rejectOnEmpty: true, // Specifying true here removes `null` from the return type!
});
// Note the `!` null assertion since TS can't know if we included
// the model or not
console.log(ourUser.projects![0].name);
}
使用非严格类型
Sequelize v5 的类型允许你定义模型而无需指定属性类型. 对于向后兼容以及在你觉得对属性进行严格检查是不值得的情况下, 这仍然是可行的.
import { Sequelize, Model, DataTypes } from 'sequelize';
const sequelize = new Sequelize('mysql://root:asd123@localhost:3306/mydb');
class User extends Model {
public id!: number; // Note that the `null assertion` `!` is required in strict mode.
public name!: string;
public preferredName!: string | null; // for nullable fields
}
User.init(
{
id: {
type: DataTypes.INTEGER.UNSIGNED,
autoIncrement: true,
primaryKey: true,
},
name: {
type: new DataTypes.STRING(128),
allowNull: false,
},
preferredName: {
type: new DataTypes.STRING(128),
allowNull: true,
},
},
{
tableName: 'users',
sequelize, // passing the `sequelize` instance is required
},
);
async function doStuffWithUserModel() {
const newUser = await User.create({
name: 'Johnny',
preferredName: 'John',
});
console.log(newUser.id, newUser.name, newUser.preferredName);
const foundUser = await User.findOne({ where: { name: 'Johnny' } });
if (foundUser === null) return;
console.log(foundUser.name);
}
使用 sequelize.define
在 v5 之前的 Sequelize 版本中, 定义模型的默认方式涉及使用 sequelize.define. 仍然可以使用它来定义模型, 也可以使用接口在这些模型中添加类型.
import { Sequelize, Model, DataTypes, Optional } from 'sequelize';
const sequelize = new Sequelize('mysql://root:asd123@localhost:3306/mydb');
// We recommend you declare an interface for the attributes, for stricter typechecking
interface UserAttributes {
id: number;
name: string;
}
// Some fields are optional when calling UserModel.create() or UserModel.build()
interface UserCreationAttributes extends Optional<UserAttributes, 'id'> {}
// We need to declare an interface for our model that is basically what our class would be
interface UserInstance
extends Model<UserAttributes, UserCreationAttributes>,
UserAttributes {}
const UserModel = sequelize.define<UserInstance>('User', {
id: {
primaryKey: true,
type: DataTypes.INTEGER.UNSIGNED,
},
name: {
type: DataTypes.STRING,
}
});
async function doStuff() {
const instance = await UserModel.findByPk(1, {
rejectOnEmpty: true,
});
console.log(instance.id);
}
如果你对模型上非严格的属性检查命令感到满意，则可以通过定义 Instance 来扩展 Model 而无需泛型类型中的任何属性, 从而节省一些代码.
import { Sequelize, Model, DataTypes } from 'sequelize';
const sequelize = new Sequelize('mysql://root:asd123@localhost:3306/mydb');
// We need to declare an interface for our model that is basically what our class would be
interface UserInstance extends Model {
id: number;
name: string;
}
const UserModel = sequelize.define<UserInstance>('User', {
id: {
primaryKey: true,
type: DataTypes.INTEGER.UNSIGNED,
},
name: {
type: DataTypes.STRING,
},
});
async function doStuff() {
const instance = await UserModel.findByPk(1, {
rejectOnEmpty: true,
});
console.log(instance.id);
}