网站源码里哪个是数据库

<?php
define('DB_HOST', 'localhost');
define('DB_USER', 'username');
define('DB_PASS', 'password');
define('DB_NAME', 'database_name');
?>

const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost:27017/database_name', {
  useNewUrlParser: true,
  useUnifiedTopology: true
});

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'database_name',
        'USER': 'username',
        'PASSWORD': 'password',
        'HOST': 'localhost',
        'PORT': '3306',
    }
}

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  database: database_name

test:
  <<: *default
  database: database_name_test

spring.datasource.url=jdbc:mysql://localhost:3306/database_name
spring.datasource.username=username
spring.datasource.password=password