sequelize left join 返回关联表的数据

Question

我有两个表，因此模型和关联将它们定义如下。

assigned_jobs
------------------------
id | job_id | emp_id 
1  |    1   | 5
2  |    2   | 6
3  |    3   | 3
4  |    4   | 2

matched_technicians
------------------------
id | job_id | emp_id 
1  |    1   | 5
2  |    1   | 6
3  |    3   | 3
4  |    3   | 2
5  |    4   | 5
6  |    4   | 6
7  |    3   | 3
8  |    3   | 2
8  |    5   | 2

因此， matched_technicians中有多个具有assigned_job id 的工作，但只记录 assignment_job 中的job_id

AssignedJob.hasMany(models.MatchedTechnicians, { sourceKey: 'job_id', foreignKey: 'job_id' })
MatchedTechnicians.hasOne(models.AssignedJob, { sourceKey: 'job_id', foreignKey: 'job_id' })

我想从matched_technicians那里获取所有这些记录，这些记录在assigned_jobs中没有该job_id的任何记录。

我在下面尝试一些东西。

let alreadyMatchedJobs = await MatchedTechnician.findAll({
    include: {
      model: AssignedJob,
      required: false,
      attributes: ['job_id'],
    },
    group: ['job_id'],
    attributes: ['job_id', 'id'],
  });

在这里，我将使用assigned_jobs加入matched_technicians并使用GROUP BY job_id获得结果
它正在生成以下查询。

SELECT `MatchedTechnician`.`job_id`, `MatchedTechnician`.`id`, `AssignedJob`.`id` AS `AssignedJob.id`, `AssignedJob`.`job_id` AS `AssignedJob.job_id`
FROM `matched_technicians` AS `MatchedTechnician`
LEFT OUTER
JOIN `assigned_jobs` AS `AssignedJob` ON `MatchedTechnician`.`job_id` 
= `AssignedJob`.`job_id`
GROUP BY `job_id`;

给出如下结果。

[
    {
        "job_id": 1,
        "id": 144,
        "AssignedJob": {
            "job_id": 1
        }
    },
    {
        "job_id": 2,
        "id": 145,
        "AssignedJob": {
            "job_id": 2
        }
    },
    {
        "job_id": 3,
        "id": 3,
        "AssignedJob": {
            "job_id": 3
        }
    },
    {
        "job_id": 4,
        "id": 2,
        "AssignedJob": {
            "job_id": 4
        }
    },
    {
        "job_id": 5,
        "id": 151,
        "AssignedJob": null
    }
]

在这里，我不明白为什么它会给出两个表中都有job_id的记录。
我只想在这里记录job_id, 5 。

Answer 1

在进行左连接时，没有明确的文档可以排除NULL值行。

我不得不做类似下面的事情。

let alreadyMatchedJobs = await MatchedTechnician.findAll({
    where: {
      '$AssignedJob.job_id$': {
        [Op.eq]: null,
      },
    },
    include: {
      model: AssignedJob,
      required: false,
    },
    group: ['job_id'],
    attributes: ['job_id', 'id'],
  });