在 sequelize 中使用另一个表连接两个表

Question

我有三个 MySQL 表： app 、 app_metadata和ecosystem 。

app表结构为：

+---------------+------------+----+---+-------+--------------+
|Field          |Type        |Null|Key|Default|Extra         |
+---------------+------------+----+---+-------+--------------+
|id             |bigint(20)  |NO  |PRI|NULL   |auto_increment|
|name           |varchar(255)|NO  |   |NULL   |              |
+---------------+------------+----+---+-------+--------------+

app_metadata 表结构为：

+---------------+------------+----+---+-------+--------------+
|Field          |Type        |Null|Key|Default|Extra         |
+---------------+------------+----+---+-------+--------------+
|id             |bigint(20)  |NO  |PRI|NULL   |auto_increment|
|app_id         |bigint(20)  |NO  |MUL|NULL   |              |
|tag_name       |varchar(255)|NO  |   |NULL   |              |
|tag_value      |text        |NO  |   |NULL   |              |
+---------------+------------+----+---+-------+--------------+

生态系统表结构为：

+---------------+------------+----+---+-------+--------------+
|Field          |Type        |Null|Key|Default|Extra         |
+---------------+------------+----+---+-------+--------------+
|id             |bigint(20)  |NO  |PRI|NULL   |auto_increment|
|name           |varchar(255)|NO  |   |NULL   |              |
+---------------+------------+----+---+-------+--------------+

我想使用 app_metadata 表中的tag_value column和 tag_name tag_name column （仅当其值为生态系统app_metadata table时）将app table与ecosystem table连接起来。

这是我试图实现这个用例的代码，但它不会产生预期的结果。 实际结果：

{
  "apps": [
    {
      "id": 1,
      "name": "EXAMPLE",
      "appMetadata": [
        {
          "id": 1,
          "tagName": "ecosystem_id",
          "tagValue": "1",
          "appId": 1,
          "ecosystem": {
            "id": 1,
            "name": "default"
          }
        },
        {
          "id": 470,
          "tagName": "vcalmic",
          "tagValue": "2",
          "appId": 1,
          "ecosystem": {
            "id": 2,
            "name": "dc/ed1"
          }
        }
      ]
    }
  ]
}

预期结果：

{
  "apps": [
    {
      "id": 1,
      "name": "EXAMPLE",
      "appMetadata": [
        {
          "id": 1,
          "tagName": "ecosystem_id",
          "tagValue": "1",
          "appId": 1,
          "ecosystem": {
            "id": 1,
            "name": "default"
          }
        },
        {
          "id": 470,
          "tagName": "vcalmic",
          "tagValue": "2",
          "appId": 1,
          "ecosystem": null
        }
      ]
    }
  ]
}

或者这个

{
  "apps": [
    {
      "id": 1,
      "name": "EXAMPLE",
      "ecosystem": {
         "id": 1,
         "name": "default"
       },
      "appMetadata": [
        {
          "id": 1,
          "tagName": "ecosystem_id",
          "tagValue": "1",
          "appId": 1
        },
        {
          "id": 470,
          "tagName": "vcalmic",
          "tagValue": "2",
          "appId": 1
        }
      ]
    }
  ]
}

Models.ecosystem.hasOne(Models.appMetadata, { foreignKey: 'tagValue' });
Models.appMetadata.belongsTo(Models.ecosystem, { foreignKey: 'tagValue' });

const options = {
  where: { accountId },
  include: [
    {
      model: Models.appMetadata,
      include: [{ model: Models.ecosystem }],
    }
  ]
};
const apps = await Models.app.findAll(options);

Answer 1

我猜你需要添加一个 required: false，在'include' object 中为 tagValue 添加一个 where 子句。 这样，当值为 1 时，它会带来生态系统。

 Models.ecosystem.hasOne(Models.appMetadata, { foreignKey: 'tagValue' }); Models.appMetadata.belongsTo(Models.ecosystem, { foreignKey: 'tagValue' }); const options = { where: { accountId }, include: [ { model: Models.appMetadata, include: [{ model: Models.ecosystem, required: false, where: {tagValue: 1}}], } ] }; const apps = await Models.app.findAll(options);