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/migrations/0001_initial.py

@@ -0,0 +1,65 @@
+# Generated by Django 5.0 on 2026-02-15 02:45
+
+import django.contrib.gis.db.models.fields
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='OfficialChusankanField',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('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(decimal_places=2, max_digits=10, verbose_name='面積(ha)')),
+                ('payment_amount', models.DecimalField(blank=True, decimal_places=0, max_digits=12, null=True, verbose_name='支払金額')),
+            ],
+            options={
+                'verbose_name': '中山間マスタ',
+                'verbose_name_plural': '中山間マスタ',
+            },
+        ),
+        migrations.CreateModel(
+            name='OfficialKyosaiField',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('k_num', models.CharField(max_length=20, unique=True, verbose_name='共済番号')),
+                ('s_num', models.CharField(blank=True, max_length=20, 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(decimal_places=2, max_digits=10, verbose_name='面積(ha)')),
+            ],
+            options={
+                'verbose_name': '共済マスタ',
+                'verbose_name_plural': '共済マスタ',
+            },
+        ),
+        migrations.CreateModel(
+            name='Field',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('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(decimal_places=4, max_digits=6, 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')),
+                ('location', django.contrib.gis.db.models.fields.PointField(blank=True, null=True, srid=4326, verbose_name='位置情報')),
+                ('chusankan_field', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='fields', to='fields.officialchusankanfield', verbose_name='関連中山間マスタ')),
+                ('kyosai_field', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='fields', to='fields.officialkyosaifield', verbose_name='関連共済マスタ')),
+            ],
+            options={
+                'verbose_name': '圃場',
+                'verbose_name_plural': '圃場',
+            },
+        ),
+    ]