接上一篇，这里使用 sequelize 来连接 postgresql 数据库
1、安装 sequelize，数据库驱动 pg
yarn add sequelize sequelize-typescript pg reflect-metadata
2、新建配置文件夹 conf 及 配置文件 db.conf.ts
/**
* @name: 数据库配置
* @param : undefined
* @return : undefined
*/
export const dbConfig = {
host: ‘localhost‘,
database: ‘demo‘,
dialect: ‘postgres‘,
username: ‘postgres‘,
password: ‘123456‘
}
3、连接数据库，新建文件夹 db 及 配置文件 db.ts
1 /*
2 * @Description: 数据库连接类
3 */
4
5 import * as path from ‘path‘
6 import { Sequelize } from ‘sequelize-typescript‘
7 import { dbConfig } from ‘../conf/db.conf‘
8
9 class DbContext {
10 private sequelize: Sequelize
11 constructor() {
12 const { host, database, dialect, username, password } = dbConfig
13 this.sequelize = new Sequelize({
14 host: host,
15 database: database,
16 dialect: dialect,
17 username: username,
18 password: password,
19 define: {
20 timestamps: true, //开启时间戳 create_at delete_at update_at
21 paranoid: true, //开启假删除
22 underscored: true, //下划线
23 charset: ‘utf8‘,
24 freezeTableName: true //固定表名为单数 默认表名是xxxs
25 },
26 pool: {
27 max: 10,
28 min: 0,
29 acquire: 30000,
30 idle: 10000
31 },
32 timezone: ‘+08:00‘,
33 modelPaths: [path.resolve(__dirname, `./models`)]
34 })
35 this.sequelize.sync()
36 }
37 init(): Boolean {
38 return !!this.sequelize
39 }
40 getInstance(): Sequelize {
41 return this.sequelize
42 }
43 isInit(): Boolean {
44 return !!this.sequelize
45 }
46 }
47 export const dbContext = new DbContext()
4、数据库实体类，新建文件夹 models 及文件 user.ts
1 /*
2 * @Description: 数据库实体类
3 */
4
5 import { Table, Column, Model } from ‘sequelize-typescript‘
6
7 @Table({
8 tableName: ‘user‘
9 })
10 export default class User extends Model<User> {
11 @Column({
12 comment: ‘自增ID‘,
13 primaryKey: true,
14 autoIncrement: true,
15 })
16 id: number
17
18 @Column
19 username: string
20
21 @Column
22 password: string
23 }
5、编写业务逻辑接口，在 src 目录下新建文件夹 dao、service，在 dao 目录下新建 UserDao.ts 及子目录 impl，在 service 目录下新建 UserService.ts 及子目录 impl
1 /*
2 * @Description: 数据库表操作基础接口 UserDao.ts
3 */
4 export interface UserDao {
5 /**
6 * @name: 查询
7 * @param :
8 * @return : Array<User>
9 */
10 findAll();
11 /**
12 * @name: 查询
13 * @param :
14 * @return : Array<User>
15 */
16 findByName(username:string);
17 /**
18 * @name: 新增
19 * @param : undefined
20 * @return : undefined
21 */
22 create(entity:UserInfo);
23
24 /**
25 * @name: 删除
26 * @param : undefined
27 * @return : undefined
28 */
29 delete(id:number);
30 }
31 export interface UserInfo {
32 username:string;
33 password:string;
34 }
1 /*
2 * @Description: service接口 UserService.ts
3 * @version:
4 */
5
6 export interface UserService{
7 /**
8 * @name: 查询
9 * @param : undefined
10 * @return : undefined
11 */
12 findAll();
13
14 /**
15 * @name: 查询
16 * @param : undefined
17 * @return : undefined
18 */
19 findByName(username:string);
20
21 /**
22 * @name: 新增
23 * @param : undefined
24 * @return : undefined
25 */
26 create(username:string,password:string);
27
28 /**
29 * @name: 删除
30 * @param : undefined
31 * @return : undefined
32 */
33 delete(id:String);
34 }
6、编写业务逻辑实现类 UserDaoImpl.ts、UserServiceImpl.ts
1 /*
2 * @Description: 数据库表操作基础实现类 UserDaoImpl.ts
3 */
4
5 import { dbContext } from ‘../../db/db‘
6 import { UserDao, UserInfo } from ‘../UserDao‘;
7 import User from ‘../../db/models/user‘;
8
9 export class UserDaoImpl implements UserDao{
10 constructor(){
11 dbContext.init();
12 }
13 /**
14 * @name: 查询
15 * @param : undefined
16 * @return : undefined
17 */
18 public async findAll(){
19 const results = await User.findAll({
20 raw: true
21 })
22 return results;
23 }
24
25 /**
26 * @name: 查询
27 * @param : undefined
28 * @return : undefined
29 */
30 public async findByName(username:string){
31 const results = await User.findOne({
32 where:{
33 username:username
34 }
35 })
36 return results;
37 }
38
39 /**
40 * @name: 新增
41 * @param : entity
42 * @return : undefined
43 */
44 public async create(entity:UserInfo) {
45 const results = await User.create(entity)
46 return results;
47 }
48
49 /**
50 * @name: 删除
51 * @param : undefined
52 * @return : undefined
53 */
54 public async delete(id: number) {
55 const results = await User.destroy({
56 where:{
57 id:{
58 $eq:id
59 }
60 }
61 });
62 return results;
63 }
64 }
1 import { UserService } from "../UserService";
2 import { UserDao } from "../../dao/UserDao";
3 import { UserDaoImpl } from "../../dao/impl/UserDaoImpl";
4
5 /*
6 * @Description: service实现类 UserServiceImpl.ts
7 */
8
9
10 export class UserServiceImpl implements UserService{
11 private userDao:UserDao;
12
13 constructor(){
14 this.userDao = new UserDaoImpl();
15 }
16
17 /**
18 * @name: 查询
19 * @param : undefined
20 * @return : undefined
21 */
22 public findAll() {
23 return this.userDao.findAll();
24 }
25 /**
26 * @name: 查询
27 * @param : undefined
28 * @return : undefined
29 */
30 public findByName(username:string) {
31 return this.userDao.findByName(username);
32 }
33 /**
34 * @name: 新增
35 * @param : entity
36 * @return : undefined
37 */
38 public create(username: string, password: string) {
39 return this.userDao.create({username,password});
40 }
41
42 /**
43 * @name: 删除
44 * @param : undefined
45 * @return : undefined
46 */
47 public delete(id: String) {
48 return this.userDao.delete(~~id);
49 }
50
51 }
7、查看成果，修改 router/index.ts
1 /*
2 * @Description: 后台路由组件
3 * @version: 0.1.0
4 */
5 import * as Router from ‘koa-router‘;
6 import { UserInfo } from ‘../dao/UserDao‘;
7 import { UserService } from ‘../service/UserService‘;
8 import { UserServiceImpl } from ‘../service/impl/UserServiceImpl‘;
9
10 const router = new Router();
11 const userService:UserService =new UserServiceImpl();
12
13 router.get(‘/*‘, async (ctx) => {
14 ctx.body = await userService.findAll();
15 })
16
17 export { router }
8、浏览器输入 http://localhost:8080
至此连接数据库完成
目录结构：
原文地址：https://www.cnblogs.com/lifefriend/p/10025469.html
时间： 2024-10-10 13:22:01