This chapter explains about how to create simple TypeORM application. Let us create a new directory named ‘TypeORM’ and move into the directory.

cd /path/to/TypeORM/

Syntax

Use below command to create new project −

typeorm init --name <project-name> --database <database-name>

Example

typeorm init --name FirstProject --database mysql

Here,

FirstProject is your project name and sqlite3 is database name. After executing the above command, you could see the following response,

Project created inside /path/to/TypeORM/FirstProject directory

Now, move in to our project directory and install project dependencies using npm module,

$ cd FirstProject 

$ npm install

Project structure

Let us understand project structure of our newly created project, FirstProject.

FirstProject 
├──> src 
│ ├──> entity 
│ │ └──> User.ts 
│ ├──> migration 
│ └──> index.ts 
├──> node_modules 
├──> ormconfig.json 
├──> package.json 
├──> package-lock.json 
└──> tsconfig.json

Here,

• src − contains source code of your application in TypeScript language. It has a file index.ts and two sub directories entity and migration.
• index.ts − Your entry point to the application.
• entity − Contains database models.
• migration − contains database migration code.
• node_modules − locally saved npm modules.
• ormconfig.json − Main configuration file of your application. It contains database configuration details and entities configuration.
• package.json − Contains node module dependencies.
• package-lock.json − Auto generated file and related to package.json.
• tsconfig.json − Contains TypeScript specific compiler options.

ormconfig.json file

Let us check the configuration option available for our application. Open ormconfig.json file and it looks similar to this −

{ 
   "type": "mysql", 
   "host": "localhost", 
   "port": 3306, 
   "username": "test", 
   "password": "test", 
   "database": "test", 
   "synchronize": true, 
   "logging": false, 
   "entities": [ 
      "src/entity/**/*.ts" ], 
   "migrations": [ "src/migration/**/*.ts" 
   ], 
   "subscribers": [ "src/subscriber/**/*.ts" 
   ], 
   "cli": { 
      "entitiesDir":"src/entity", "migrationsDir":"src/migration", "subscribersDir":"src/subscriber
   }    
 }

Here,

type, host, username, password, database and port options are related to database setting. mysql can be configured using below configuration −

{ 
   "type": "mysql", 
   "host": "localhost", 
   "port": 3306, 
   "username": "db_username", "password": "db_password", "database": "db_name" 
}

• entities − refers the location of your entity classes.
• migrations − refers the location of your migration classes.
• subscribers − refers the location of your subscriber classes.
• cli − refers the option used by TypeORM CLI to auto generate the code

Start MySql server

Before starting the application, start your MySQL server or any database server used by you and make sure it is running properly.

Run application

Once everything is configured, we can execute the application using the below command −

npm start

You could see the following response −

> [email protected] start /Users/../../TypeORM/FirstProject 

> ts-node src/index.ts 

Inserting a new user into the database... Saved a new user with id: 1 Loading users from the database... Loaded users: [ User { id: 1, firstName: ''Timber'', lastName: ''Saw'', age: 25 }] 

Here you can setup and run express/koa/any other framework.

The application inserted a new user into the database and then reverse load it from the database and finally show the loaded user in the console. We have successfully created a new TypeORM application, configured it and run the application.

We will discuss about how the data is executed elaborately in upcoming chapters.