Django 3.2 - 具有相同表的原始 SQL 查询（模型）

Question

我们已将一些数据库表从我们的生产环境迁移到 django ORM，并在 django 之外自动同步这些表。 → 到目前为止效果很好，但是我们在 django 中无法正确连接这些表（模型）。

models.py

class SsdaSdgadr(models.Model):
    sda_sdgid = models.ForeignKey(SsdgSendung, on_delete=models.CASCADE, blank=True, null=True)
    sda_satid = models.CharField(max_length=4, blank=True, null=True)
    sda_adrid = models.ForeignKey(SadrAdresse, on_delete=models.CASCADE, blank=True, null=True)
    sda_ref = models.CharField(max_length=35, blank=True, null=True)
    sda_termbis = models.DateField(blank=True, null=True)
    sda_termvon = models.DateField(blank=True, null=True)

    class Meta:
        db_table = 'ssda_sdgadr'
        unique_together = (('sda_sdgid', 'sda_satid'),)

class SsdgSendung(models.Model):
    sdg_sdgid = models.CharField(primary_key=True, max_length=30)
    sdg_konz = models.CharField(max_length=12, blank=True, null=True)

    class Meta:
        db_table = 'ssdg_sendung'

class SadrAdresse(models.Model):
    adr_adrid = models.IntegerField(primary_key=True)
    adr_name1 = models.CharField(max_length=35, blank=True, null=True)
    adr_name2 = models.CharField(max_length=35, blank=True, null=True)

    class Meta:
        db_table = 'sadr_adresse'

样本数据

SsdaSdgadr：

sdg_sdgid	sda_satid	sda_adrid	sda_ref	sda_termvon	sda_termbis
BL-1237781-BL-1	IV	169550	'00123/4539999'	''	''
BL-1237781-BL-1	SU	555555	''	01.12.2021	02.12.2021
BL-1237781-BL-1	CN	999999	'00123'	02.12.2021	13.12.2021

views.py

我使用以下原始 SQL

    Sendungen = SsdaSdgadr.objects.raw('''
        SELECT 
            IV.id,
            IV.sda_sdgid_id,
            IV.sda_ref,
            SU.id,
            SU.sda_adrid_id as ABS,
            SU.sda_termvon,
            CN.id,
            CN.sda_adrid_id as EMPF,
            CN.sda_termbis
        FROM 
            ssda_sdgadr IV
            INNER JOIN ssdg_sendung on sdg_sdgid = IV.sda_sdgid_id
            INNER JOIN ssda_sdgadr SU on SU.sda_sdgid_id = IV.sda_sdgid_id and SU.sda_satid="SU"
            INNER JOIN ssda_sdgadr CN on CN.sda_sdgid_id = IV.sda_sdgid_id and CN.sda_satid="CN"
        WHERE IV.sda_satid="IV"
        GROUP BY
            IV.id,
            IV.sda_sdgid_id,
            IV.sda_ref,
            SU.id,
            SU.sda_adrid_id,
            SU.sda_termvon,
            CN.id,
            CN.sda_adrid_id,
            CN.sda_termbis
        ORDER BY
            sdg_datum desc
    ''')
...
response = render(request, 'cust/home.html', {
            'Sendungen': Sendungen,
        })
return response

模板上的结果适用于字段“SU.sda_termvon”和“CN.sda_termbis”，但不适用于字段“sda_adrid”（→ 仅显示 IV.sda_adrid_id 的结果）。

模板代码

 {% for la_item in Sendungen %}
                        <tr>
                            <td>{{ la_item.sda_sdgid.sdg_sdgid }}</td>
                            <td>{{ la_item.sda_ref }}</td> <!-- IV.sda_ref OKAY -->
                            <td>{{ la_item.sda_adrid.adr_adrid }}</td> <!-- is IV.sda_adrid NOT OKAY -->
                            <td>{{ la_item.sda_adrid.adr_adrid }}</td> <!-- is IV.sda_adrid NOT OKAY -->
                            <td>{{ la_item.sda_termvon|date }}</td> <!-- SU.sda_termvon OKAY -->
                            <td>{{ la_item.sda_termbis|date }}</td> <!-- CN.sda_termbis OKAY -->
                        </tr>
 {% endfor %}

如何访问模板上的结果“CN.sda_adrid_id”和“SU.sda_adrid_id”？ → 看起来 ORM 对原始 SQL 的解释与数据库不同：

DB-Result & Desired result 应该如下所示：

sda_sdgid_id	IV.sda_ref	SU.sda_adrid_id	CN.sda_adrid	SU.termvon	CN.termbis
BL-1237781-BL-1	1920192/4530210220/0881760357	555555	999999	01.12.2021	13.12.2021

我的实际结果是这样的：

sda_sdgid_id	IV.sda_ref	IV.sda_adrid_id	IV.sda_adrid_id	SU.termvon	CN.termbis
BL-1237781-BL-1	1920192/4530210220/0881760357	169550	169550	01.12.2021	13.12.2021

Answer 1

我使用了这个解决方法（“SsdaSdgadr”的模型属性），它给了我想要的结果：

models.py

class SsdaSdgadr(models.Model):
    sda_sdgid = models.ForeignKey(SsdgSendung, on_delete=models.CASCADE, blank=True, null=True)
    sda_satid = models.CharField(max_length=4, blank=True, null=True)
    sda_adrid = models.ForeignKey(SadrAdresse, on_delete=models.CASCADE, blank=True, null=True)
    sda_ref = models.CharField(max_length=35, blank=True, null=True)
    sda_termbis = models.DateField(blank=True, null=True)
    sda_termvon = models.DateField(blank=True, null=True)

    class Meta:
        db_table = 'ssda_sdgadr'
        unique_together = (('sda_sdgid', 'sda_satid'),)

    @property
    def is_adr_su(self):
        return  SsdaSdgadr.objects.filter(sda_sdgid = self.sda_sdgid, sda_satid = "SU")

    @property
    def is_adr_cn(self):
        return  SsdaSdgadr.objects.filter(sda_sdgid = self.sda_sdgid, sda_satid = "CN")

views.py

Sendungen = SsdaSdgadr.objects.filter(Q(sda_satid__in=["IV"])).order_by('-sda_sdgid__sdg_datum')
...
response = render(request, 'cust/home.html', {
            'Sendungen': Sendungen,
        })
return response

模板代码 home.html

{% for la_item in Sendungen %}
<tr>
 <td>{{ la_item.sda_sdgid.sdg_sdgid }}</td>
 <td>{{ la_item.sda_ref }}</td> <!-- IV.sda_ref OKAY -->
 {% for adr in la_item.is_adr_su %}
   <td>{{ adr.sda_adrid.adr_adrid }}</td> <!-- SU.sda_adrid OKAY -->
   <td>{{ adr.sda_termvon|date }}</td> <!-- SU.sda_termvon OKAY -->
 {% endfor %}
 {% for adr in la_item.is_adr_cn %}
   <td>{{ adr.sda_adrid.adr_adrid }}</td> <!-- CN.sda_adrid OKAY -->
   <td>{{ adr.sda_termbis|date }}</td> <!-- CN.sda_termbis OKAY -->
 {% endfor %}
</tr>
{% endfor %}