Sequelize 查询在多对多关系中显示附加数据

Posted 2023-03-07

【中文标题】Sequelize 查询在多对多关系中显示附加数据

【英文标题】：Sequelize query shows additional data in Many to Many relationship

【发布时间】：2021-05-18 20:01:18

【问题描述】：

我有这个设置，用户和主题之间的多对多关系：

User.belongsToMany(Topic, through: "UserTopics", timestamps: false);
Topic.belongsToMany(User, through: "UserTopics", timestamps: false);

我尝试获取所有用户及其主题，这个查询做得很好：

User.findAll(
    attributes:  exclude: ["password"] ,
    include: [
       model: Topic, attributes: ['id', 'name',] 
    ]
  )

这是它的输出：

[
    
        "id": 1,
        "firstName": "John",
        "lastName": "Doe",
        "CNP": "123",
        "email": "[e-mail]",
        "validated": false,
        "createdAt": "2021-02-15T21:46:52.000Z",
        "updatedAt": "2021-02-15T21:46:52.000Z",
        "topics": [
            
                "id": 1,
                "name": "crypto",
                "UserTopics": 
                    "userId": 1,
                    "topicId": 1
                
            ,
         ...
     ,
     ...
]

但我遇到的问题是我无法弄清楚为什么会发生这种情况是 UserTopics 属性会针对用户拥有的每个主题显示。

我该如何摆脱它？

【参考方案1】：

阅读此https://sequelize.org/master/manual/advanced-many-to-many.html

如果您想从结果中排除关联字段：

User.findAll(
    attributes:  exclude: ["password"] ,
    include: [
       model: Topic, attributes: ['id', 'name',] 
    ],
    through: 
      attributes: []
    
)

【参考方案2】：

感谢fatur 指出页面。 这样做的实际方法与他写的有点不同。 “through”属性必须在数组对象内部，像这样：

User.findAll(
    attributes:  exclude: ["password"] ,
    include: [
        
            model: Topic,
            attributes: ["id", "name"],
            through: 
                attributes: []
            
        
    ]
)