Nestjs联合Typeorm操作Mysql数据库

单张表增删改查

创建项目

// 安装脚手架(只需要安装一次,因为这个是全局的)
npm i -g @nestjs/cli
// 创建项目
nest new project-name
// (该过程有个选择包管理工具的,我选的yarn)

启动项目

yarn run start:dev
// 可以在浏览器访问localhost:3000  输出helloWorld

安装typeorm,mysql2和@nestjs/typeorm

// 安装依赖
yarn add --save @nestjs/typeorm typeorm mysql2
// @nestjs/typeorm这个本人运行上面命令一直安装不上,只好单独安装一下就成功了(yarn add @nestjs/typeorm)

创建实体模块

nest g res user2

连接数据库(app.module.ts)

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { TypeOrmModule } from '@nestjs/typeorm';
import { User2Module } from './user2/user2.module';
@Module({imports: [TypeOrmModule.forRoot({type: 'mysql',host: 'localhost',port: 3306,username: 'root',password: 'admin',database: 'shop',autoLoadEntities: true,synchronize: true,}),User2Module,],controllers: [AppController],providers: [AppService],
})
export class AppModule {}

上面将框架搭建完成了,后面都是对代码的修改

/src/user2/entities/user2.entity.ts

import { Entity, Column, PrimaryGeneratedColumn } from 'typeorm';@Entity()
export class User2 {@PrimaryGeneratedColumn()id: number;@Column()firstName: string;@Column()lastName: string;@Column({ default: true })isActive: boolean;
}

/src/user2/user2.module.ts

import { Module } from '@nestjs/common';
import { User2Service } from './user2.service';
import { User2Controller } from './user2.controller';
// 引入实体
import { User2 } from './entities/user2.entity';
// 引入orm框架
import {TypeOrmModule} from '@nestjs/typeorm'
@Module({imports:[TypeOrmModule.forFeature([User2])],controllers: [User2Controller],providers: [User2Service],
})
export class User2Module {}

到这一步,运行项目会发现数据库多出来一张user2的表,表字段和user2.entity.ts一一对应
接下来三个文件内都是逻辑代码

/src/user2/dto/create-user2.dto.ts

// 这里在添加数据用上了
export class CreateUser2Dto {firstName: string;lastName: string;isActive: boolean;
}

/src/user2/user2.controller.ts

import {Controller,Get,Post,Body,Patch,Param,Delete,Query,DefaultValuePipe,ParseIntPipe,
} from '@nestjs/common';
import { User2Service } from './user2.service';
import { CreateUser2Dto } from './dto/create-user2.dto';
import { UpdateUser2Dto } from './dto/update-user2.dto';@Controller('user2')
export class User2Controller {constructor(private readonly user2Service: User2Service) {}@Post() // 这里添加数据使用了apifox,调至post接口,Body-json类型,将添加的字段依次输入即可,直接发请求 http://localhost:3000/user2async create(@Body() createUser2Dto: CreateUser2Dto) {const res = await this.user2Service.create(createUser2Dto);if (res.generatedMaps.length > 0) {return {success: '添加成功',};} else {error: '添加失败';}return this.user2Service.create(createUser2Dto);}// 查询所有@Get()findAll(@Query('current', new DefaultValuePipe(1), ParseIntPipe) current: number, // 页数,默认值为1,int类型@Query('pagesize', new DefaultValuePipe(15), ParseIntPipe) pagesize: number, // 每页条数,默认值15) {// 传入当前页数,number类型的return this.user2Service.findAll(current, pagesize);}// 查询单条信息@Get(':id')findOne(@Param('id', ParseIntPipe) id: number) {// 将id类型转换为int类型限制为number类型return this.user2Service.findOne(+id);}// 更新(修改数据) 这里修改数据使用了apifox,调至post接口,Body-json类型,将添加的字段依次输入即可,直接发请求 http://localhost:3000/user2/3@Patch(':id')async update(@Param('id') id: string,@Body() updateUser2Dto: UpdateUser2Dto,) {const user = await this.user2Service.findOne(+id);if (user === null) {return {error: '没有此用户,暂时无法修改',};}const res = await this.user2Service.update(+id, updateUser2Dto);if (res.affected > 0) {return {success: '修改成功',};} else {error: '修改失败';}}// 根据id删除单个用户@Delete(':id')async remove(@Param('id') id: number) {// 先查询到这个用户(这里直接调用根据id查询用户的方法)const user = await this.user2Service.findOne(id); // 在findOne这个方法里面的findOne是使用了promise,因此这里需要异步一下if (user === null) {return { error: '删除的用户不存在' };}const res = this.user2Service.remove(+id);if ((await res).affected > 0) {return {success: '删除成功',};} else {error: '删除失败';}}
}

src/user2/user2.service.ts

import { Injectable } from '@nestjs/common';
import { CreateUser2Dto } from './dto/create-user2.dto';
import { UpdateUser2Dto } from './dto/update-user2.dto';
import { InjectRepository } from '@nestjs/typeorm';
// 1.导入实体
import { User2 } from './entities/user2.entity';
// 2.导入依赖注入
import { Repository } from 'typeorm';
@Injectable()
export class User2Service {// 3.需要对数据库进行操作,这里需要进行依赖注入constructor(@InjectRepository(User2)private user2Repoitory: Repository<User2>,) {}// 新增数据(这里需要用到dto层进行逻辑处理)create(createUser2Dto: CreateUser2Dto) {return this.user2Repoitory.insert(createUser2Dto);}// 查询数据findAll(current = 1, pagesize = 15) {// 查询所有的逻辑代码()(访问localhost:3000/user2)// return this.user2Repoitory.findAndCount();// 分页查询的代码return this.user2Repoitory.findAndCount({skip: (current - 1) * pagesize, // 跳过多少页take: pagesize, // 当前页数});}// 根据id查询findOne(id: number) {// 根据id查询用户信息// return this.user2Repoitory.findOneBy({ id });// 也可以使用findone查询,这个查询毕竟灵活return this.user2Repoitory.findOne({ where: { id } }); // 里面放查询条件}// 更新(修改数据)update(id: number, updateUser2Dto: UpdateUser2Dto) {// 根据id修改数据return this.user2Repoitory.update(id,updateUser2Dto);}// 根据id删除用户remove(id: number) {return this.user2Repoitory.delete(id);}
}

关联表(一对一)的增删改查

创建项目

// 创建项目
nest new project-name
// (该过程有个选择包管理工具的,我选的yarn)

启动项目

yarn run start:dev
// 可以在浏览器访问localhost:3000  输出helloWorld

安装typeorm,mysql2和@nestjs/typeorm

// 安装依赖
yarn add --save @nestjs/typeorm typeorm mysql2
// @nestjs/typeorm这个本人运行上面命令一直安装不上,只好单独安装一下就成功了(yarn add @nestjs/typeorm)

创建实体模块

nest g res user2

连接数据库(app.module.ts)

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { TypeOrmModule } from '@nestjs/typeorm';
import { UserModule } from './user/user.module';
import { User2Module } from './user2/user2.module';
@Module({imports: [TypeOrmModule.forRoot({type: 'mysql',host: 'localhost',port: 3306,username: 'root',password: 'admin',database: 'shop',autoLoadEntities: true,synchronize: true,}),UserModule,User2Module,],controllers: [AppController],providers: [AppService],
})
export class AppModule {}

上面将框架搭建完成了,后面都是对代码的修改

/src/user2/entities/user2.entity.ts

import { Entity, Column, PrimaryGeneratedColumn, OneToOne } from 'typeorm';
import { Idcard } from './idcard.entity';@Entity()
export class User2 {@PrimaryGeneratedColumn()id: number;@Column()firstName: string;@Column()lastName: string;@Column()age: number;@Column({ default: true })isActive: boolean;// 需要第二个参数 , 外键是在idcard这个表的user2字段// 在incard是通过JoinColumn()做的关联 , 下面这个第二个参数指定了外键名称(这样的话,如果外键存在则是删除不掉这个user2表的)@OneToOne(()=>Idcard,(idcard)=>idcard.user2)idCard:Idcard
}

同级创建Idcard.entity.ts文件,内容如下:(代表第二张表)

import { User2 } from 'src/user2/entities/user2.entity';
import {Column,Entity,JoinColumn,OneToOne,PrimaryGeneratedColumn,
} from 'typeorm';
@Entity()
export class Idcard {@PrimaryGeneratedColumn()id: number;@Column({ length: 50, comment: '身份证号' })cardname: string;// 指定一对一的关系@JoinColumn() // 这里必须要连接下,否则外键加不上@OneToOne(() => User2, { // 这里代表的是关联关系onDelete: 'CASCADE',onUpdate: 'CASCADE',cascade: true, // 关联关系保存})user2: User2; // 绑定的外键
}

/src/user2/user2.module.ts

import { Module } from '@nestjs/common';
import { User2Service } from './user2.service';
import { User2Controller } from './user2.controller';
// 引入实体
import { User2 } from './entities/user2.entity';
import { Idcard } from './entities/idcard.entity';
// 引入orm框架
import { TypeOrmModule } from '@nestjs/typeorm';
@Module({imports: [TypeOrmModule.forFeature([User2,Idcard])],controllers: [User2Controller],providers: [User2Service],
})
export class User2Module {}

到这一步,运行项目会发现数据库多出来一张user2和idcard的表,表字段和entity.ts一一对应
接下来三个文件内都是逻辑代码

/src/user2/dto/create-user2.dto.ts

// 这里在添加数据用上了
export class CreateUser2Dto {firstName: string;lastName: string;isActive: boolean;
}

/src/user2/user2.controller.ts

import { Controller, Get, Post, Body, Patch, Param, Delete } from '@nestjs/common';
import { User2Service } from './user2.service';
import { CreateUser2Dto } from './dto/create-user2.dto';
import { UpdateUser2Dto } from './dto/update-user2.dto';@Controller('user2')
export class User2Controller {constructor(private readonly user2Service: User2Service) {}@Post()create(@Body() createUser2Dto: CreateUser2Dto) {return this.user2Service.create(createUser2Dto);}@Get()findAll() {return this.user2Service.findAll();}@Get(':id')findOne(@Param('id') id: string) {return this.user2Service.findOne(+id);}@Patch(':id')update(@Param('id') id: string, @Body() updateUser2Dto: UpdateUser2Dto) {return this.user2Service.update(+id, updateUser2Dto);}@Delete(':id')remove(@Param('id') id: string) {return this.user2Service.remove(+id);}
}

/src/user2/user2.service.ts

import { Injectable } from '@nestjs/common';
import { CreateUser2Dto } from './dto/create-user2.dto';
import { UpdateUser2Dto } from './dto/update-user2.dto';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User2 } from './entities/user2.entity';
import { Idcard } from './entities/idcard.entity';@Injectable()
export class User2Service {constructor(@InjectRepository(User2) private user2: Repository<User2>,@InjectRepository(Idcard) private idcard: Repository<Idcard>,) {}// 插入数据create(createUser2Dto: CreateUser2Dto) {const user2 = new User2();user2.firstName = '我是';user2.lastName = '扎代';user2.age = 20;// 接下来是第二张表要添加的数据const idcard = new Idcard();idcard.cardname = '123456';idcard.user2 = user2; // 进行绑定关联关系// 最后进行保存,这里只要Idcard配置了cascade:true就可以自动进行关联关系的保存,即这里只需要保存idcard就可以自动保存user了,不用保存两次return this.idcard.save(idcard);}findAll() {return `This action returns a user2`;}// 关联查询findOne(id: number) {return this.user2.find({relations: ['idCard'], // 这个是关联表的外表列名(当查找到对应的数据时,user2也会打印出关联表信息),如果不写的话,关联表信息不会被查出来where: {id: id,},});}// 修改数据update(id: number, updateUser2Dto: UpdateUser2Dto) {const user2 = new User2();user2.id = 1; // 这里需要指定一下id(因为id是自增的,不指定一下id会相当于是添加数据)user2.firstName = '我是';user2.lastName = '扎代';user2.age = 20;// 接下来是第二张表要添加的数据const idcard = new Idcard();idcard.id = 1; // 这里需要指定一下id(因为id是自增的,不指定一下id会相当于是添加数据)idcard.cardname = '123456';idcard.user2 = user2; // 进行绑定关联关系// 最后进行保存,这里只要Idcard配置了cascade:true就可以自动进行关联关系的保存,即这里只需要保存idcard就可以自动保存user了,不用保存两次return this.idcard.save(idcard);}// 删除数据async remove(id: number) {let res = await this.idcard.delete(1);let res2 = await this.user2.delete(1);if (res.affected > 0 && res2.affected > 0) {return { success: '删除成功' };} else {return { error: '删除失败' };}}
}

关联表(一对多,多对一)的增删改查

接下来会在刚刚一对一项目基础上去做修改

在user2和Idcard同级创建两个表(员工表和部门表)

多个员工只有一个部门,但是一个部门可以有很多员工,这样就对应了一对多的关系

员工表 /src/user2/entities/Employee.eneity.ts

import { Entity, PrimaryGeneratedColumn, Column, ManyToOne } from 'typeorm';
import { Department } from './Department.eneity';
// 员工表
@Entity()
export class Employee {@PrimaryGeneratedColumn()id: number;@Column()name: string;// 多的一方(员工),很多个员工对应一个部门// 为什么不需要JoinColumn()这个装饰器,因为这种多对一的关系,外键是知道的(外键在多的一方)@ManyToOne(() => Department, {cascade: true,})department: Department;
}

部门表 /src/user2/entities/Department.eneity.ts

import { Entity, PrimaryGeneratedColumn, Column, OneToMany } from 'typeorm';
import { Employee } from './Employee.eneity';
// 部门表
@Entity()
export class Department {@PrimaryGeneratedColumn()id: number;@Column()name: string;// 一个部门有很多个员工,第二个参数代表外键在哪里维护@OneToMany(() => Employee, (emp) => emp.department)employee: Employee[];
}

在模块里面注入一下 /src/user2/user2.module.ts

import { Module } from '@nestjs/common';
import { User2Service } from './user2.service';
import { User2Controller } from './user2.controller';
// 引入实体
import { User2 } from './entities/user2.entity';
import { Idcard } from './entities/idcard.entity';
import { Employee } from './entities/Employee.eneity';
import { Department } from './entities/Department.eneity';
// 引入orm框架
import { TypeOrmModule } from '@nestjs/typeorm';
@Module({imports: [TypeOrmModule.forFeature([User2,Idcard,Employee,Department])],controllers: [User2Controller],providers: [User2Service],
})
export class User2Module {}

此时启动项目会创建两个新表,可以查看外键看关系,一对多和多对一这种关系外键都在多的一方
下面就只需要修改/src/user2/user2.servics.ts进行增删改查就行了

import { Injectable } from '@nestjs/common';
import { CreateUser2Dto } from './dto/create-user2.dto';
import { UpdateUser2Dto } from './dto/update-user2.dto';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User2 } from './entities/user2.entity';
import { Idcard } from './entities/idcard.entity';
import { Department } from './entities/Department.eneity';
import { Employee } from './entities/Employee.eneity';@Injectable()
export class User2Service {constructor(@InjectRepository(User2) private user2: Repository<User2>,@InjectRepository(Idcard) private idcard: Repository<Idcard>,@InjectRepository(Department) private department: Repository<Department>,@InjectRepository(Employee) private employee: Repository<Employee>,) {}// 插入数据create(createUser2Dto: CreateUser2Dto) {// 这是一对多的写法(会打印出多的一方每个人的数据)// const d1 = new Department();// d1.name = '技术部';// const e1 = new Employee();// e1.name = '张三';// e1.department = d1; // 关联关系绑定// const e2 = new Employee();// e2.name = '李四';// e2.department = d1; // 关联关系绑定// const e3 = new Employee();// e3.name = '王五';// e3.department = d1; // 关联关系绑定// 最后进行保存,这里只要Idcard配置了cascade:true就可以自动进行关联关系的保存,即这里只需要保存idcard就可以自动保存user了,不用保存两次// return this.employee.save([e1, e2, e3]);// 这是多对一的写法,打印出的也是最外层是多的一方,内部是每一个员工对象const e1 = new Employee();e1.name = '张三';const e2 = new Employee();e2.name = '李四';const e3 = new Employee();e3.name = '王五';const d1 = new Department();d1.name = '技术部';d1.employee = [e1, e2, e3];return this.department.save([e1, e2, e3]);}findAll() {return `This action returns a user2`;}// 关联查询findOne(id: number) {console.log('id', id);return this.department.find({// department查询的表名relations: ['employee'], // 这个是关联表的外表列名(当查找到对应的数据时,user2也会打印出关联表信息)where: {id: id,},});}// 修改数据update(id: number, updateUser2Dto: UpdateUser2Dto) {// 这里和一对一是一致的,只需要修改id即可}// 删除数据async remove(id: number) {// 删除的话,需要将关联的employee删了,再删除department,找到当前id项const department = await this.department.findOne({relations: ['employee'],where: { id },});// 如果找到这个数据了,把他关联的员工找到if (department) {const employeesToDelete = department.employee;// 先清空员工await this.employee.remove(employeesToDelete);// 再删除数据await this.department.delete(id);return 1;} else {// Handle the case when the department with the given ID is not foundreturn 0;}}
}

关联表(多对多)的增删改查

还是基于刚刚代码,在实体类创建Article.entity.ts和Tag.entity.ts文件

文章和文章标签存在多对多关系

/src/user2/entities/Article.entity.ts

import {Entity,PrimaryGeneratedColumn,Column,ManyToMany,JoinTable,
} from 'typeorm';
import { Tag } from './Tag.entity';
@Entity()
export class Article {@PrimaryGeneratedColumn()id: number;@Column()title: string;@Column()content: string;// 建立多对多的关系,需要个中间表@JoinTable() // 指定中间表,(这个是自动创建的,运行项目就等创建完数据库就会发现的,中间表绑定的是另外两张表的id)// 多对多关系的所有表都要指定第二个参数,找到外键位置@ManyToMany(() => Tag, (a) => a.articles, {cascade: true,onDelete: 'CASCADE', // 设置级联删除,这样无论这样只要任意一方被删除,与之相关的数据都会同步删除onUpdate: 'CASCADE',})tag: Tag[];
}

/src/user2/entities/Tag.entity.ts

import { Entity, PrimaryGeneratedColumn, Column, ManyToMany } from 'typeorm';
import { Article } from './Article.entity';
@Entity()
export class Tag {@PrimaryGeneratedColumn()id: number;@Column()name: string;// 删除这里,比如我想删除一篇文章,也会删除标签tag,但是万一别的文章也有tag引用怎么解决???// 那就只能给标签加个多对多属性,指定外键列在哪里//   // 多对多关系的所有表都要指定第二个参数,找到外键位置@ManyToMany(() => Article, (a) => a.tag) // 指定外键列位置articles: Article[];
}

在模块里面注入一下 /src/user2/user2.module.ts

import { Module } from '@nestjs/common';
import { User2Service } from './user2.service';
import { User2Controller } from './user2.controller';
// 引入实体
import { User2 } from './entities/user2.entity';
import { Idcard } from './entities/idcard.entity';
import { Employee } from './entities/Employee.eneity';
import { Department } from './entities/Department.eneity';
import { Tag } from './entities/Tag.entity';
import { Article } from './entities/Article.entity';
// 引入orm框架
import { TypeOrmModule } from '@nestjs/typeorm';
@Module({imports: [TypeOrmModule.forFeature([User2,Idcard,Employee,Department,Article,Tag,]),],controllers: [User2Controller],providers: [User2Service],
})
export class User2Module {}

最后都是在service里面进行的代码了,代码如下

/src/user2/user2.service.ts

import { Injectable } from '@nestjs/common';
import { CreateUser2Dto } from './dto/create-user2.dto';
import { UpdateUser2Dto } from './dto/update-user2.dto';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { User2 } from './entities/user2.entity';
import { Idcard } from './entities/idcard.entity';
import { Department } from './entities/Department.eneity';
import { Employee } from './entities/Employee.eneity';
import { Article } from './entities/Article.entity';
import { Tag } from './entities/Tag.entity';@Injectable()
export class User2Service {constructor(@InjectRepository(User2) private user2: Repository<User2>,@InjectRepository(Idcard) private idcard: Repository<Idcard>,@InjectRepository(Department) private department: Repository<Department>,@InjectRepository(Employee) private employee: Repository<Employee>,@InjectRepository(Article) private article: Repository<Article>,@InjectRepository(Tag) private tag: Repository<Tag>,) {}// 插入数据create(createUser2Dto: CreateUser2Dto) {// 多对多const a1 = new Article();a1.title = 'aaa';a1.content = 'aaaaaa';const a2 = new Article();a2.title = 'bbb';a2.content = 'bbbbbb';const t1 = new Tag();t1.name = '111';const t2 = new Tag();t2.name = '222';const t3 = new Tag();t3.name = '333';// 绑定关系a1.tag = [t1, t2];a2.tag = [t1, t2, t3];return this.article.save([a1, a2]); //因为在实体类设置了自动保存,因此这个文章保存了标签是自动关联保存的// this.tag.save([t1, t2, t3]);}findAll() {return `This action returns a user2`;}// 关联查询findOne(id: number) {return this.article.find({// department查询的表名relations: ['tag'], // 这个是关联表的外表列名(当查找到对应的数据时,user2也会打印出关联表信息)// where: {//   id: id,// },});}// 修改数据async update(id: number, updateUser2Dto: UpdateUser2Dto) {const a1 = await this.article.findOne({relations: ['tag'],where: {id: id,},});console.log('a1', a1);a1.title = 'ccccc';a1.tag = a1.tag.filter((item) => item.name.includes('ttt111'));// 修改完以后再保存return this.article.save(a1);}// 删除数据async remove(id: number) {// 由于article外键设置了级联删除,因此需要先删除article才能删除对应的taglet res = await this.article.delete(id);let res2 = await this.tag.delete(id);if (res.affected > 0 && res2.affected > 0) {return {success: '删除成功',};}return {error: '删除失败',};}
}

本次笔记参考此视频学习的