Laravel框架，同时连接2个数据库

1.在env内，写入两个数据库的信息

#默认连接
DB_CONNECTION=mysql
DB_HOST=localhost    //连接地址
DB_PORT=3306
DB_DATABASE=database //数据库名称
DB_USERNAME=admin    //数据库账号
DB_PASSWORD=admin    //数据库密码

#第二个数据库连接
DB_HOST_GH=192.168.1.1  //第二个数据库的连接地址
DB_PORT_GH=3306
DB_DATABASE_GH=database2   //数据库名称
DB_USERNAME_GH=admin2      //数据库账号
DB_PASSWORD_GH=admin2      //数据库密码

2.在config文件夹内，找到database.php，在connections内加入代码信息

'connections' => [

        'sqlite' => [
            'driver' => 'sqlite',
            'database' => env('DB_DATABASE', database_path('database.sqlite')),
            'prefix' => '',
        ],

        //第一个数据库连接
        'mysql' => [
            'driver' => 'mysql',
            'host' => env('DB_HOST', '127.0.0.1'),
            'port' => env('DB_PORT', '3306'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', ''),
            'unix_socket' => env('DB_SOCKET', ''),
            'charset' => 'utf8mb4',
            'collation' => 'utf8mb4_unicode_ci',
            'prefix' => 'his_',
            'strict' => false,
            'engine' => null,
        ],

        //第二个数据库连接
        'mysql_gh' => [
            'driver' => 'mysql',
            'host' => env('DB_HOST_GH','192.168.1.1'),
            'port' => env('DB_PORT_GH', '3306'),
            'database' => env('DB_DATABASE_GH', 'forge'),
            'username' => env('DB_USERNAME_GH', 'forge'),
            'password' => env('DB_PASSWORD_GH', ''),
            'charset' => 'utf8mb4',
            'collation' => 'utf8mb4_unicode_ci',
            'prefix' => '',
            'strict' => false,
            'engine' => null,
        ]

    ],

3.controller使用数据库连接时，代码实例：

$res = DB::connection('mysql_gh');//连接第二个数据库
$data = $res->select("SELECT * FROM user WHERE username='张三'");

或者

$data = DB::connection('mysql_gh')->select("SELECT * FROM user WHERE username='张三'");