嵌套：无法创建名为“默认”的新连接，因为具有该名称的连接已经存在并且它现在具有活动连接 session

Question

I am trying to create a seeder file in nestjs, the problem is when I run the project using start:dev, somehow nestjs also start seed.ts file with main.ts file. How can I make nestjs not start seed file when I run the project either on prod/dev but seed must be called only when I run the seed script.

Here is the seed.ts code

 import { NestFactory } from '@nestjs/core' import { Logger } from '@nestjs/common' import { SeederModule } from './database/seeder.module' import { Seeder } from './database/seeder' async function bootstrap() { NestFactory.createApplicationContext(SeederModule).then((appContext) => { const logger = appContext.get(Logger) const seeder = appContext.get(Seeder) seeder.seedRoles().then(() => { logger.debug('Seeding Roles complete.') }).catch((error) => { logger.error('Seeding Roles failed.') throw error }) seeder.seedAdmin().then(() => { logger.debug('Seeding Admin complete.') }).catch((error) => { logger.error('Seeding Admin failed!') throw error }) .finally(() => appContext.close()) }) .catch((error) => { throw error }) } bootstrap()

Here is the main.ts file for nestJS

 import { Logger, ValidationPipe } from '@nestjs/common' import { NestFactory } from '@nestjs/core' import { AppModule } from './modules/app/app.module' async function bootstrap() { const app = await NestFactory.create(AppModule) app.enableCors() const port = process.env.PORT || 3000 app.useGlobalPipes(new ValidationPipe()) await app.listen(port).then(() => { Logger.log(`App listening on port ${port}`) }).catch((err) => { Logger.log(`Error while connecting to port ${port}`, err) }) } bootstrap()

And here is the package.json file

 { "name": "jugg-website", "version": "0.0.1", "description": "", "author": "", "private": true, "license": "UNLICENSED", "scripts": { "prebuild": "rimraf dist", "build": "nest build", "format": "prettier --write \"src/**/*.ts\" \"test/**/*.ts\"", "start": "nest start", "start:dev": "link-module-alias && nest start --watch", "start:debug": "nest start --debug --watch", "start:prod": "node dist/main", "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix", "test": "jest", "test:watch": "jest --watch", "test:cov": "jest --coverage", "test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand", "test:e2e": "jest --config./test/jest-e2e.json", "seed": "ts-node -r tsconfig-paths/register src/seed.ts" }, "dependencies": { "@nestjs/common": "^7.6.13", "@nestjs/core": "^7.6.13", "@nestjs/jwt": "^7.2.0", "@nestjs/passport": "^7.1.5", "@nestjs/platform-express": "^7.6.13", "@nestjs/typeorm": "^7.1.5", "class-transformer": "^0.4.0", "class-validator": "^0.13.1", "config": "^3.3.6", "link-module-alias": "^1.2.0", "passport": "^0.4.1", "pg": "^8.5.1", "reflect-metadata": "^0.1.13", "rimraf": "^3.0.2", "rxjs": "^6.6.6", "typeorm": "^0.2.32" }, "devDependencies": { "@nestjs/cli": "^7.5.6", "@nestjs/schematics": "^7.2.7", "@nestjs/testing": "^7.6.13", "@types/express": "^4.17.11", "@types/jest": "^26.0.20", "@types/node": "^14.14.31", "@types/supertest": "^2.0.10", "@typescript-eslint/eslint-plugin": "^4.15.2", "@typescript-eslint/parser": "^4.15.2", "eslint": "^7.20.0", "eslint-config-prettier": "^8.1.0", "eslint-plugin-prettier": "^3.3.1", "jest": "^26.6.3", "prettier": "^2.2.1", "supertest": "^6.1.3", "ts-jest": "^26.5.2", "ts-loader": "^8.0.17", "ts-node": "^9.1.1", "tsconfig-paths": "^3.9.0", "typescript": "^4.1.5" }, "jest": { "moduleFileExtensions": [ "js", "json", "ts" ], "rootDir": "src", "testRegex": ".*\\.spec\\.ts$", "transform": { "^.+\\.(t|j)s$": "ts-jest" }, "collectCoverageFrom": [ "**/*.(t|j)s" ], "coverageDirectory": "../coverage", "testEnvironment": "node" } }

Answer 1

you can try setting KeepConnectionAlive option to true in typeOrm configuration in the app.module file https://github.com/nestjs/typeorm/issues/61