多个表中的 Django 查询集

Question

我有这种使用PostgreSQL的查询：

SELECT 
tbl_project_lu.project_id, 
tbl_project_lu.house_id,
tbl_project_lu.project_name AS project, 
tbl_house_lu.house_name, 
tbl_project_lu.description,
tbl_house_mbr.person_id
FROM ((tbl_house_lu INNER JOIN tbl_house_mbr ON tbl_house_lu.house_id = tbl_house_mbr.house_id) 
  INNER JOIN tbl_project_lu ON tbl_house_lu.house_id = tbl_project_lu.house_id) 
  INNER JOIN tbl_proj_mbr ON (tbl_project_lu.project_id = tbl_proj_mbr.project_id) 
  AND (tbl_house_mbr.house_mbr_id = tbl_proj_mbr.house_mbr_id) 
WHERE person_id = 'foo';

这是model.py：

class tbl_house_lu(models.Model):
    house_name =    models.CharField(max_length=30, null=False)
    house_id =      models.AutoField(primary_key=True, null=False)


class tbl_house_mbr(models.Model):
    house_id =      models.ForeignKey(tbl_house_lu, db_column='house_id', on_delete=models.CASCADE)
    person_id =     models.ForeignKey(tbl_person_lu, db_column='person_id', on_delete=models.CASCADE)  


class tbl_project_lu(models.Model):
    project_id=     models.AutoField(primary_key=True, null=False)
    house_id=       models.ForeignKey(tbl_house_lu, db_column='house_id', on_delete=models.CASCADE)
    project_name=   models.CharField(max_length=100, null=False)
    description=    models.CharField(max_length=100, null=True)


class tbl_proj_mbr(models.Model):
    project_id=     models.ForeignKey(tbl_project_lu, db_column='project_id', on_delete=models.CASCADE)
    house_mbr_id=   models.ForeignKey(tbl_house_mbr, db_column='house_mbr_id', on_delete=models.CASCADE)

在 django 中使用这种查询的最佳方式是什么？ Django ORM 可以处理这种查询还是我必须为此使用存储过程？

Answer 1

使用 select_related() 将预先填充适当的属性：

一个示例定义了 3 个模型（City、Person、Book）及其依赖项。

see select_related doc