yii2项目连接多个数据库

web.php配置，引入或者直接设置db

我的是引入

$db = require __DIR__ . '/db.php';

components下设置

'db' => $db['db'],

'db2' => $db['db2'],

db.php文件，设置成自己的数据库配置

<?php

return [
    'db' => [
        'class' => 'yii\db\Connection',
        'dsn' => env('db_dsn'),
        'username' => env('db_username'),
        'password' => env('db_password'),
        'charset' => env('db_charset'),
    ],
    'db2' => [
        'class' => 'yii\db\Connection',
        'dsn' => env('db2_dsn'),
        'username' => env('db2_username'),
        'password' => env('db2_password'),
        'charset' => env('db2_charset'),
    ],

    // Schema cache options (for production environment)
    'enableSchemaCache' => env('db_enableSchemaCache'),
    'schemaCacheDuration' => env('db_schemaCacheDuration'),
    'schemaCache' => env('db_schemaCache'),

    'enableProfiling'=>true,
];

在模型中使用特定的db连接

public static function getDb()
    {
        return Yii::$app->db2;
    }

测试了一下，如果不设置，默认连接的是db