typescript - 续写 TypeScript 中的模型 getter

Question

正确的使用方法是什么this.getDataValue在 getter function使用 TypeScript 时的 Sequelize 模型？

这是我得到的错误:

Property 'getDataValue' does not exist on type 'string | DataTypeAbstract | DefineAttributeColumnOptions'.

Property 'getDataValue' does not exist on type 'string'.

我的模型定义:

import * as Sequelize from 'sequelize';
import sequelize from '../db-connection';

export interface IUserAttributes {
    date_of_birth: Date;
    name: string;
}

export interface IUserInstance extends Sequelize.Instance<IUserAttributes> {
    date_of_birth: Date;
    name: string;
}

const User = sequelize.define<IUserAttributes, IUserInstance>('user', {
    name: {
        type: Sequelize.STRING,
        validate: {
            notEmpty: true,
        },
    },
    date_of_birth: {
        get(): Date {
            return new Date(this.getDataValue('date_of_birth'));
        },
        type: Sequelize.DATEONLY,
        validate: {
            isDate: true,
            notEmpty: true,
        },
    },
});

export default User;

Answer 1

您需要为 this 指定类型在 getter 函数中

const User = sequelize.define<IUserAttributes, IUserInstance>('user', {
  name: {
      type: Sequelize.STRING,
      validate: {
          notEmpty: true,
      },
  },
  date_of_birth: {
      get(this: IUserInstance): Date {
          return new Date(this.getDataValue('date_of_birth'));
      },
      type: Sequelize.DATEONLY,
      validate: {
          isDate: true,
          notEmpty: true,
      },
  },
});

备注 this参数不会发送给 JS，它只是为了 typescript 编译器的好处。