Lumen框架多数据库连接配置方法

Lumen作为一款API导向很浓的框架，配置极简化，默认只支持一路DB配置

然而随着业务复杂度的提高，引入多个数据库连接似乎无法避免，下面介绍一下LUMEN连接多个数据库的配置方法：
修改.env文件，增加新DB配置，如下：

//DB1 配置

DB_CONNECTION=mysql

DB_HOST=127.0.0.1

DB_PORT=3306

DB_DATABASE=dbname

DB_USERNAME=dbname

DB_PASSWORD=password

DB_TIMEOUT=4

//DB2配置

DB_TEST_CONNECTION=mysql

DB_TEST_HOST=127.0.0.1

DB_TEST_PORT=3307

DB_TEST_DATABASE=dbname2

DB_TEST_USERNAME=dbname2

DB_TEST_PASSWORD=password

DB_TEST_TIMEOUT=4

因为LUMEN在加载DB配置时，还是会默认去laravel模块下寻找相关配置文件，这时修改laravel模块下的database.php文件

文件位置在:

./vendor/laravel/lumen-framework/config/database.php

添加.env文件中新增的DB配置，如下：

//默认配置
'mysql' => [
'driver'    => 'mysql',
'host'      => env('DB_HOST', 'localhost'),
'port'      => env('DB_PORT', 3306),
'database'  => env('DB_DATABASE', 'forge'),
'username'  => env('DB_USERNAME', 'forge'),
'password'  => env('DB_PASSWORD', ''),
'charset'   => env('DB_CHARSET', 'utf8'),
'collation' => env('DB_COLLATION', 'utf8_unicode_ci'),
'prefix'    => env('DB_PREFIX', ''),
'timezone'  => env('DB_TIMEZONE', '+00:00'),
'strict'    => env('DB_STRICT_MODE', false),
],

//新增配置
'mysql_test'=>[
'driver'    => 'mysql',
'host'      => env('DB_TEST_HOST', 'localhost'),
'port'      => env('DB_TEST_PORT', 3306),
'database'  => env('DB_TEST_DATABASE', 'forge'),
'username'  => env('DB_TEST_USERNAME', 'forge'),
'password'  => env('DB_TEST_PASSWORD', ''),
'charset'   => env('DB_CHARSET', 'utf8'),
'collation' => env('DB_COLLATION', 'utf8_unicode_ci'),
'prefix'    => env('DB_PREFIX', ''),
'timezone'  => env('DB_TIMEZONE', '+00:00'),
'strict'    => env('DB_STRICT_MODE', false),
],

在项目中调用时，直接按database.php中的做法初始化connection就行，如下：

$query = app('db')->connection("mysql_test")->select("...");