Yii2连接多个数据库

1、使用高级模板 yii2-app-advanced

2、设置 common\config\main-local.php 本地文件

'components' => [
        'db' => [
            'class' => 'yii\db\Connection',
            'dsn' => 'mysql:host=localhost;dbname=yii2advanced',
            'username' => 'root',
            'password' => '',
            'charset' => 'utf8',
        ],
        // 连接另个数据库，注意使用gii生成的时候选择对应的数据库
        'blogdb' => [
            'class' => 'yii\db\Connection',
            'dsn' => 'mysql:host=localhost;dbname=blogdb',
            'username' => 'root',
            'password' => '',
            'charset' => 'utf8',
            // 'tablePrefix' => 'cp_', // 表前缀
        ],
        'mailer' => [
            'class' => 'yii\swiftmailer\Mailer',
            'viewPath' => '@common/mail',
            // send all mails to a file by default. You have to set
            // 'useFileTransport' to false and configure a transport
            // for the mailer to send real emails.
            'useFileTransport' => true,
        ],
       ...
    ],

3、第三步

  3.1、第一种，使用 gii模式生成Model、controllers等，

    - 选择更改的数据库名 Database Connection ID 改为 blogdb

    - Table Name 改为 blogdb 中数据表名称 post

  生成后的 models 中的模板 Post.php 中自动含有连接 blogdb 数据库的方法

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

  3.2、手动创建对应 model 

<?php

namespace common\models;

use Yii;

/**
 * This is the model class for table "post".
 *
 * @property int $id
 * @property string $title
 * @property string $content
 * @property string|null $tags
 * @property int $status
 * @property int|null $create_time
 * @property int|null $update_time
 * @property int $author_id
 *
 * @property Adminuser $author
 * @property Comment[] $comments
 * @property Poststatus $status0
 */
class Post extends \yii\db\ActiveRecord
{
    /**
     * {@inheritdoc}
     */
    public static function tableName()
    {
        return 'post';
    }

    /**
     * @return \yii\db\Connection the database connection used by this AR class.
     */
    public static function getDb()
    {
        return Yii::$app->get('blogdb');
    }

    /**
     * {@inheritdoc}
     */
    public function rules()
    {
        return [
            [['title', 'content', 'status', 'author_id'], 'required'],
            [['content', 'tags'], 'string'],
            [['status', 'create_time', 'update_time', 'author_id'], 'integer'],
            [['title'], 'string', 'max' => 128],
            [['author_id'], 'exist', 'skipOnError' => true, 'targetClass' => Adminuser::class, 'targetAttribute' => ['author_id' => 'id']],
            [['status'], 'exist', 'skipOnError' => true, 'targetClass' => Poststatus::class, 'targetAttribute' => ['status' => 'id']],
        ];
    }

    /**
     * {@inheritdoc}
     */
    public function attributeLabels()
    {
        return [
            'id' => 'ID',
            'title' => 'Title',
            'content' => 'Content',
            'tags' => 'Tags',
            'status' => 'Status',
            'create_time' => 'Create Time',
            'update_time' => 'Update Time',
            'author_id' => 'Author ID',
        ];
    }

    /**
     * Gets query for [[Author]].
     *
     * @return \yii\db\ActiveQuery
     */
    public function getAuthor()
    {
        return $this->hasOne(Adminuser::class, ['id' => 'author_id']);
    }

    /**
     * Gets query for [[Comments]].
     *
     * @return \yii\db\ActiveQuery
     */
    public function getComments()
    {
        return $this->hasMany(Comment::class, ['post_id' => 'id']);
    }

    /**
     * Gets query for [[Status0]].
     *
     * @return \yii\db\ActiveQuery
     */
    public function getStatus0()
    {
        return $this->hasOne(Poststatus::class, ['id' => 'status']);
    }
}