typescript-koa-postgresql 实现一个简单的rest风格服务器 —— 连接 postgresql 数据库

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：