Day 3 のデータモデル実装が完了しました。

完了内容
models.py
fields/models.py:
- OfficialKyosaiField - 共済マスタ
- OfficialChusankanField - 中山間マスタ
- Field - 圃場（PointField で位置情報対応）
plans/models.py:
- Crop - 作物マスタ
- Variety - 品種マスタ（unique_together 制約）
- Plan - 作付け計画（unique_together 制約）
admin.py
- 全てのモデルを admin に登録
- list_display, search_fields, list_filter 設定
- FieldAdmin は GIS 用 GISModelAdmin を使用
マイグレーション
✅ makemigrations - 成功
✅ migrate - 成功
管理画面 (http://localhost:8000/admin) で全てのモデルが確認・編集できます。

backend/apps/fields/models.py

@@ -1,3 +1,65 @@
+from django.contrib.gis.db import models as gis_models
 from django.db import models
 
-# Create your models here.
+
+class OfficialKyosaiField(models.Model):
+    k_num = models.CharField(max_length=20, unique=True, verbose_name="共済番号")
+    s_num = models.CharField(max_length=20, blank=True, null=True, verbose_name="枝番")
+    address = models.CharField(max_length=255, verbose_name="住所")
+    kanji_name = models.CharField(max_length=100, verbose_name="漢字名")
+    area = models.DecimalField(max_digits=10, decimal_places=2, verbose_name="面積(ha)")
+
+    class Meta:
+        verbose_name = "共済マスタ"
+        verbose_name_plural = "共済マスタ"
+
+    def __str__(self):
+        return f"{self.k_num} ({self.kanji_name})"
+
+
+class OfficialChusankanField(models.Model):
+    c_id = models.CharField(max_length=20, unique=True, verbose_name="中山間ID")
+    oaza = models.CharField(max_length=100, verbose_name="大字")
+    aza = models.CharField(max_length=100, verbose_name="字")
+    chiban = models.CharField(max_length=50, verbose_name="地番")
+    area = models.DecimalField(max_digits=10, decimal_places=2, verbose_name="面積(ha)")
+    payment_amount = models.DecimalField(max_digits=12, decimal_places=0, blank=True, null=True, verbose_name="支払金額")
+
+    class Meta:
+        verbose_name = "中山間マスタ"
+        verbose_name_plural = "中山間マスタ"
+
+    def __str__(self):
+        return f"{self.c_id} ({self.oaza}{self.aza})"
+
+
+class Field(models.Model):
+    name = models.CharField(max_length=100, verbose_name="圃場名")
+    address = models.CharField(max_length=255, verbose_name="住所")
+    area_tan = models.DecimalField(max_digits=6, decimal_places=4, verbose_name="面積(反)")
+    area_m2 = models.IntegerField(verbose_name="面積(m2)")
+    owner_name = models.CharField(max_length=100, verbose_name="所有者名")
+    kyosai_field = models.ForeignKey(
+        OfficialKyosaiField,
+        on_delete=models.SET_NULL,
+        blank=True,
+        null=True,
+        related_name='fields',
+        verbose_name="関連共済マスタ"
+    )
+    chusankan_field = models.ForeignKey(
+        OfficialChusankanField,
+        on_delete=models.SET_NULL,
+        blank=True,
+        null=True,
+        related_name='fields',
+        verbose_name="関連中山間マスタ"
+    )
+    location = gis_models.PointField(blank=True, null=True, verbose_name="位置情報")
+
+    class Meta:
+        verbose_name = "圃場"
+        verbose_name_plural = "圃場"
+
+    def __str__(self):
+        return self.name