> For the complete documentation index, see [llms.txt](https://eleven-fifty-academy.gitbook.io/javascript-152-nodeserver/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://eleven-fifty-academy.gitbook.io/javascript-152-nodeserver/js_library/node-server/13-more-sequelize-functions/migrations/01-init-and-config.md).

# 01 - init and config

The first step in performing a migration is to create the necessary files and folders. `sequelize init` does this process for us.

## Running Sequelize init

1. Open a terminal window and navigate to your server folder.
2. In the terminal window, run `sequelize init`. This will create the following folders: `config`, `models`, `migrations`, and `seeders`. The table below goes into more detail on the purpose of each folder.

   *NOTE*: We already have a `models` folder, so that part is skipped.
3. Look at your project in VS Code. You should see all of the new folders.

| Folder     | Purpose                                                         |
| ---------- | --------------------------------------------------------------- |
| config     | The configuration settings for your database migrations.        |
| migrations | The actual migration files. *More on this later*.               |
| models     | The files used to create your tables.                           |
| seeders    | Files that can add data to your database. *More on this later*. |

## config.js

Inside the `config` folder, open `config.json`. We need to make a few changes to give Sequelize the ability to access our database. Currently, the file looks like this:

```javascript
{
  "development": {
    "username": "root",
    "password": null,
    "database": "database_development",
    "host": "127.0.0.1",
    "dialect": "mysql"
  },
  "test": {
    "username": "root",
    "password": null,
    "database": "database_test",
    "host": "127.0.0.1",
    "dialect": "mysql"
  },
  "production": {
    "username": "root",
    "password": null,
    "database": "database_production",
    "host": "127.0.0.1",
    "dialect": "mysql"
  }
}
```

You can see that nothing here points to our database right now. Additionally, there are several different environments available: `development`, `test`, and `production`. For our purposes, it doesn't matter which environment is used, but there are times when it will. For now, we'll just change everything to what we need. Delete the information in `config.js` and add the following:

```javascript
{
  "development": {
    "username": "postgres", //1
    "password": "YOUR-POSTGRES-PASSWORD-HERE",  //2
    "database": "workoutlog", //3
    "host": "127.0.0.1",
    "port": "5432", //4
    "dialect": "postgres" //5
  },
  "test": {
    "username": "postgres",
    "password": "YOUR-POSTGRES-PASSWORD-HERE",
    "database": "workoutlog",
    "host": "127.0.0.1",
    "port": "5432",
    "dialect": "postgres"
  },
  "production": {
    "username": "postgres",
    "password": "YOUR-POSTGRES-PASSWORD-HERE",
    "database": "workoutlog",
    "host": "127.0.0.1",
    "port": "5432",
    "dialect": "postgres"
  }
}
```

Here's what changed: 

1\. The local postgres username to `postgres` 

2\. Your postgres password. 

3\. The name of your database. 

4\. We have to add the `port` property so that Sequelize can talk to the database on the right port. 

5\. Sequelize can interact with several different versions of SQL databases, each with a slightly different syntax for SQL queries. This tells Sequelize what we are currently using.