NestJS连接数据库和typeorm的用法

1、安装依赖

npm install --save @nestjs/typeorm typeorm mysql

2、在项目的根目录下创建一个ormconfig.json文件

{
  "type": "mysql",
  "host": "地址",
  "port": 3306,
  "username": "账号",
  "password": "密码",
  "database": "数据库",
  "entities": ["dist/**/*.entity{.ts,.js}"],
  "synchronize": false  //不会在数据库自动生成表，我个人不太喜欢这种，所以自己写的原生sql
}

此处可能会有一个错误，typeorm版本和最新的nestjs略有不兼容，须参考bug fix部分做修改
参考此篇文章解决

image.png

点击查看解决BUG方法

3、在app.module.ts文件中使用数据库的配置

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { CatModule } from './cat/cat.module';
// 引入数据库的及配置文件
import { TypeOrmModule, TypeOrmModuleOptions } from '@nestjs/typeorm';

@Module({
  imports: [
    CatModule,
    TypeOrmModule.forRoot(), // 数据库的
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

4、创建一个entities文件夹，下面放实体类，例如form.entity.ts的实体类

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

@Entity("trainee")
export class FormEntity extends BaseEntity {
  @PrimaryGeneratedColumn()
  id: number;
  @Column({ type: "varchar", name: "name" })
  name: string;
  @Column({ type: "bigint", name: "phone" })
  phone: number;
  @Column({ type: "varchar", name: "email" })
  email: string;
  @Column({ type: "varchar", name: "university" })
  university: string;
  @Column({ type: "varchar", name: "major" })
  major: string;
  @Column({ type: "int", name: "position" })
  position: number;
  @Column({ type: "int", name: "city" })
  city: number;
  @Column({ type: "varchar", name: "vita" })
  vita: string;
  @Column({ type: "datetime", name: "createTime" })
  createTime: string;
}

5、在form.module.ts中注册实体类Rents

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { FormEntity } from 'src/entities/form.entity';
import { FormController } from './form.controller';
import { FormService } from './form.service';

@Module({
  imports: [TypeOrmModule.forFeature([FormEntity])],
  controllers:[FormController],
  providers: [FormService]
})
export class FormModule { }

6、在服务层@InjectRepository() 修饰器向 RentService 注入 RentRepository

import { HttpException, HttpStatus, Injectable } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { FormEntity } from '../../entities/form.entity'
import { Repository } from 'typeorm';
import { FormReq } from 'src/interfaces/form.interface';

@Injectable()
export class FormService {
  constructor(
    @InjectRepository(FormEntity)
    private readonly formRepository: Repository
  ) { }

  async submit(submitFormReq: FormReq) {
    try {
      return await this.formRepository.save(submitFormReq)
    } catch {
      throw new HttpException("服务器错误，请稍后再试", HttpStatus.FORBIDDEN)
    }
  }
}

TypeOrm的一些使用

• 1、save（添加数据到数据库）

  return await this.formRepository.save(submitFormReq)

• 2、使用where条件查询数据

return await this.progressListEntity.find({ where: { status: 1 } })

• 3、使用原生sql语句

  const res = await this.progressListEntity.query("select max(step) as max from recruitment_progress;")