NestJS入门4：MySQL typeorm 增删改查

前文参考：

NestJS入门1

NestJS入门2：创建模块

NestJS入门3：不同请求方式前后端写法

1. 安装数据库相关模块

npm install @nestjs/typeorm typeorm mysql -S

2. MySql中创建数据库

3. 添加连接数据库代码

app.module.ts

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { UserModule } from "./user/user.module";
import { TypeOrmModule } from "@nestjs/typeorm";

@Module({
  imports: [UserModule,
    TypeOrmModule.forRoot({
      type: "mysql",
      host: "localhost",
      port: 3306,
      username: "root",
      password: "root",
      database: "user",
      entities: ["dist/**/*.entity{.ts,.js}"],
      synchronize: true,
    }),],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

4. 创建数据表

user/entities/user.entity.ts修改为

import { Column, Entity, PrimaryGeneratedColumn } from "typeorm";

@Entity("user")//数据表名称,由本程序创建
export class UserEntity {
  @PrimaryGeneratedColumn()
  id: number; // 标记为主键，值自动生成

  @Column({ length: 20 })
  username: string;

  @Column({ length: 20 })
  password: string;

  @Column({ type: "timestamp", default: () => "CURRENT_TIMESTAMP" })
  create_time: Date;

  @Column({ type: "timestamp", default: () => "CURRENT_TIMESTAMP" })
  update_time: Date;
}

以上代码重新运行后，可以看到数据表

5. user.module导入并注册实体

import { Module } from '@nestjs/common';
import { UserService } from './user.service';
import { UserController } from './user.controller';
import { UserEntity } from "./entities/user.entity"; //增加语句
import { TypeOrmModule } from "@nestjs/typeorm"; // 增加语句

@Module({
  imports: [TypeOrmModule.forFeature([UserEntity])], //增加语句：导入并注册实体
  controllers: [UserController],
  providers: [UserService],
})
export class UserModule {}

6. user.services增加数据库操作

import { Injectable } from '@nestjs/common';
import { CreateUserDto } from './dto/create-user.dto';
import { UpdateUserDto } from './dto/update-user.dto';
import { UserEntity } from './entities/user.entity';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';


@Injectable()
export class UserService {

  constructor(
    @InjectRepository(UserEntity)
    private userRepository: Repository<UserEntity>,
  ) {}

// 增加
  async create(createUserDto: CreateUserDto) {
    this.userRepository.save(createUserDto);
  }

// 查询所有
  async findAll() {
    return await this.userRepository.find();
  }

// 查询特定
async findOne(id: number) {
  return await this.userRepository.findOne({where:{id:id}});
  }

 // 更新 
 async  update(id: number, updateUserDto: UpdateUserDto) {
    return await this.userRepository.update({id:id}, updateUserDto);
  }

 // 删除  
async  remove(id: number) {
  return await this.userRepository.delete({id:id});
  }
}

user.controller.ts不需要修改

import { Controller, Get, Post, Body, Patch, Param, Delete } from '@nestjs/common';
import { UserService } from './user.service';
import { CreateUserDto } from './dto/create-user.dto';
import { UpdateUserDto } from './dto/update-user.dto';

@Controller('user')
export class UserController {
  constructor(private readonly userService: UserService) {}

  // POST http://localhost:3000/user  Body加上X-www-form-urlencoded数据   
  @Post()
  create(@Body() createUserDto: CreateUserDto) {
    return this.userService.create(createUserDto);
  }

//GET http://localhost:3000/user
  @Get()
  findAll() {
    console.log('Get');
    return this.userService.findAll();
  }


  //GET http://localhost:3000/user/1
  @Get(':id')
  findOne(@Param('id') id: string) {
    console.log('Get ' + id);
    return this.userService.findOne(+id);
  }

  //PATCH http://localhost:3000/user/1  Body加上数据
  @Patch(':id')
  update(@Param('id') id: string, @Body() updateUserDto: UpdateUserDto) {
    console.log('Patch ' + id);
    console.log(UpdateUserDto);
    return this.userService.update(+id, updateUserDto);
  }
  
//DELETE http://localhost:3000/user/1 
  @Delete(':id')
  remove(@Param('id') id: string) {
    console.log('Delete ' + id);
    return this.userService.remove(+id);
  }
}