如何连接mongo和nestJs？

npm install --save @nestjs/mongoose mongoose

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';

@Module({
  imports: [
    MongooseModule.forRoot('mongodb://localhost:27017/mydatabase'),
  ],
})
export class AppModule {}

import { Schema, Prop, SchemaFactory } from '@nestjs/mongoose';
import { Document } from 'mongoose';

@Schema()
export class Cat extends Document {
  @Prop()
  name: string;

  @Prop()
  age: number;
}

export const CatSchema = SchemaFactory.createForClass(Cat);

import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';
import { Cat } from './cat.model';

@Injectable()
export class CatsService {
  constructor(@InjectModel(Cat.name) private catModel: Model<Cat>) {}

  async create(cat: Cat): Promise<Cat> {
    const createdCat = new this.catModel(cat);
    return createdCat.save();
  }

  async findAll(): Promise<Cat[]> {
    return this.catModel.find().exec();
  }
}

import { Controller, Get, Post, Body } from '@nestjs/common';
import { CatsService } from './cats.service';
import { Cat } from './cat.model';

@Controller('cats')
export class CatsController {
  constructor(private readonly catsService: CatsService) {}

  @Post()
  async create(@Body() cat: Cat) {
    return this.catsService.create(cat);
  }

  @Get()
  async findAll() {
    return this.catsService.findAll();
  }
}

npm run start